Posts Tagged ‘Evolution’

On birth rates, abortions and “eugenics by default”

July 20, 2013

Selective breeding works.

Humans have applied it – and very successfully – for plants and animals since antiquity.

There is nothing “wrong” conceptually with eugenics for the selective breeding of humans. But the Nazis – and not only the Nazis – brought all of eugenics into disrepute by the manner in which they tried to apply the concept.  Because of the Nazis and the coercive treatment of some minorities in Europe and of the Aborigines in Australia where forced sterilisation, forced abortions, genocide, euthanasia and mass murder were used to try and control the traits of future generations, eugenics has come to be inextricably associated with the methods used. Even in more recent times genocide, mass rapes and mass murder have been evident even if not openly for the purpose of controlling the genetic characteristics of the survivors.

I note that evolution by “natural selection” does not intentionally select for any particular traits. Surviving traits are due to the deselection of individuals who have not the wherewithal to survive until reproduction. Natural Selection in that sense is not pro-active and evolution is merely the result of changing environments which causes individuals of a species who cannot cope with the change to perish. Evolution has no direction of its own and is just the result of who survives an environmental change. It is not not some great force which “selects” or  leads a species into a desired future. Species fail when the available spread of traits and characteristics among the existing individuals of that species is not sufficient to generate some individuals who can survive the environmental change. Natural Selection is therefore not an intentional selection process but represents the survivors of change. Of course, not all traits have a direct influence on survival. All “collateral” traits are carried along – coincidentally and unintentionally –  with those traits which do actually help survival in any particular environment. But as conditions change what was once a collateral trait may become one which assists in survival.

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When is a strawberry dead?

June 25, 2013

An interesting discussion yesterday on BBC Radio

What Is Death?

Series 8 Episode 1 of 6 Monday 24 June 2013

“What Is Death?”

In the first of a new series of the award winning science/comedy series, Brian Cox and Robin Ince are joined on stage by comedian Katy Brand, biochemist Nick Lane and forensic anthropologist Sue Black to discuss why death is such an inevitable feature of a living planet. As well as revisiting such weighty scientific issues, such as when can a strawberry, be truly declared to be dead, they’ll also explore the scientific process of death, its evolutionary purpose and whether it is scientifically possibly to avoid it all together.

The death of a strawberry had apparently been discussed on an earlier program last year:

Brian Cox Strawberry

A fascinating discussion regarding when a cell can be truly considered “dead” though I couldn’t quite agree that death was necessary to evolution. Only birth is of course. It would be pretty crowded without death but life – or death – after procreation no longer has any part to play in the passing on of genes to the next generation or on evolution. With immortality there would, of course, be no need for procreation or for any future generations. But if immortal beings did beget other immortal beings then an Infinite Universe would come in very handy. However, the fertility rate needed for replenishment of the mortal members of a species is unconnected to the longevity of the individuals and I cannot see that death, per se, has any impact on evolution.

As far as the life and death of a strawberry are concerned it seemed to me that the question was essentially meaningless. You could as well ask if your finger could be alive when it no longer was connected to your body. A finger -like a strawberry is never truly alive unless connected to the body that it is a part of and the question of life or death when it is separated from its host body is moot.

Self-replicating fingers – or strawberries – would make John Wyndham’s Triffids seem benign.

The future for human evolution

June 25, 2013

The future of human evolution is secure as we develop into more robust species.

From The Onion:

Image of Mollusca

ANN ARBOR, MI—In a breakthrough study that researchers say adds important insight into the evolution of Homo sapiens, scientists at the University of Michigan confirmed Thursday that human beings are slowly evolving into mollusks. “Evidence shows that modern humans emerged on the evolutionary timeline about 200,000 years ago, developed into the highly evolved hominids of today, and are now transforming into soft-bodied invertebrates,” said the study’s lead author Dr. Mitch Keneally, adding humans have already started turning into snails, slugs, and octopi, evidenced by their increasingly amorphous figures. “Over the next 1,000 years, we’re going to see people developing gills, a hard protective shell around their torsos, and a large, muscular foot in their dorsal region that will help with locomotion and mucus secretion. The world is changing rapidly, and those who can’t filter seawater aren’t going to be able to survive.” Scientists added that the evolutionary trajectory isn’t all that surprising considering that mollusks themselves descended from monkeys just 5,000 years ago.

Future human evolution will be selection by deselection

June 6, 2013

io9 carries  a look at how science fiction treats evolution :The most ludicrous depictions of evolution in science fiction history.

Of course this begs the question as to how humans are likely to evolve over the coming generations?

Humans and chimpanzees ancestors split some 7-8 million years ago and it took some 350,000 generations after that divergence for evolution by natural selection to produce anatomically modern humans (AMH). (This of course raises the question as to how chimpanzee evolution proceeded to reach modern chimpanzees while humans were developing into homo sapiens?).

It has been only about 10,000 generations since AMH appeared and only some 6,000 generations or so since modern humans left Africa. A very short time in evolutionary terms yet in this period humans have evolved to exhibit the various races of man that exist today. This differentiation is primarily superficial and all humans existing are capable of mating and producing viable offspring with each other. In theory humans existing today would also be compatible and – in the main – capable of mating with the humans of 6,000 generations ago. In practice a meeting of modern humans with those from 120,000 years ago would be an exaggerated replica of modern man meeting with isolated tribes in the 20th century. These isolated branches of humanity generally had lower levels of immunity to the bacteria carried by their distant cousins and were ravaged by disease after such encounters. The bacteria we carry are probably greatly different to those that humans carried at the dawn of anatomically modern humans. Probably no such meeting or mating would be very successful and one or both would probably succumb to disease brought on by the other’s bacteria. Nevertheless the genomes of the two – even after 6,000 generations – would  not be so very different and probably still be compatible. In any primate species a generational distance of over 20,000 between individuals will probably disqualify any theoretical possibility of successful mating.

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Sense and nonsense : The Aquatic Ape Theory

May 9, 2013

The Aquatic Ape Theory is one that the mainstream loves to lampoon and ridicule (here and here for example). For the first time in some 50 years a conference on the subject is being currently held in London — much to the disgust of main-stream evolutionists.

But for all the ridicule, the fact remains that we do not yet have a satisfactory explanation for how modern humans came to shed their fur, developed bi-pedalism and developed a layer of fat under our skins. The “consensus” theory that climate change caused forests to change to savannahs and forced primates to leave the trees, walk on two legs to use their hands, start running to catch prey,  discard their fur to stay cool and develop sweat glands to get rid of the heat generated, actually has almost as many holes as the Aquatic Theory.

Maybe some integration of these theories is necessary. Or perhaps there is a better theory waiting to be found. In any event, I have a natural suspicion of all science which has to invoke a “consensus” to justify itself.  But more importantly I just like the idea of some idyllic, aquatic interlude in our ancient past.

But whatever the truth of it,  Elaine Morgan is always entertaining and well worth listening to. As she puts it  “You cannot stave off the Aquatic Theory to protect a vacuum. … History is strewn with cases when we have all got it wrong!”

“Bearing children has largely become the province of the lower classes”

May 2, 2013

The Daily Mail runs an article today about why the middle class are not breeding any more. It is not difficult to get a faint whiff of eugenics. But I can’t help feeling that some level of eugenics is not necessarily all bad as we move from natural selection to a world where artificial selection (IVF, surrogacy, sperm banks etc.) is increasing. And of course, even the availability of abortion on demand is in itself a form of selection.

  • Educated women deferring motherhood for so long they’re no longer fertile
  • Bearing children ‘has largely become the province of the lower classes’ 
  • TV historian Dr Lucy Worsley is poster girl for intentionally childless women

…. as author and demographic expert Jonathan Last observes in his controversial book What to Expect When No One’s Expecting:

‘The bearing and raising of children has largely become the province of the lower classes. It’s a kind of reverse Darwinism where the traditional markers of success make one less likely to reproduce.’

If “lower class” were a genetic trait then the middle and higher classes should fear extinction in due course. Fortunately “class” is just relative and subjective so no matter what the demographics are, distinctions of class will be introduced into any population that exists. But what is more interesting to consider is the fact that women with a higher level of education (which says nothing about native intelligence) have fewer children. This seems to be a global phenomenon. Data from 2010 in the extract below.

The full table is here. Primary School Enrollment and Total Fertility Rates, Latest Year (2000-2010)

Primary School Enrollment and Total Fertility Rates for Selected Countries, Latest Year 2000 – 2010

Rank Country

Primary School Enrollment

Total Fertility Rate

Percent

Number of children
per woman

1 Japan

100.0

1.3

2 Spain

99.8

1.5

3 Iran

99.7

1.8

4 Georgia

99.6

1.6

5 United Kingdom

99.6

1.9

181 Equitorial Guinea

53.5

5.3

182 Guinea-Bissau

52.1

5.7

183 Djibouti

40.1

3.9

184 Sudan

39.2

4.2

185 Eritrea

35.7

4.6

Note: Rankings are based on a list of 185 countries for which primary enrollment data are available.
Source: EPI from UNESCO

Fertility rates tend to be highest in the world’s least developed countries. When mortality rates decline quickly but fertility rates fail to follow, countries can find it harder to reduce poverty. Poverty, in turn, increases the likelihood of having many children, trapping families and countries in a vicious cycle. Conversely, countries that quickly slow population growth can receive a “demographic bonus”: the economic and social rewards that come from a smaller number of young dependents relative to the number of working adults.

For longer term population stability the goal is to reach replacement-level fertility, which is close to 2 children per woman in places where mortality rates are low. Industrial countries as a group have moved below this level. Some developing countries have made progress in reducing fertility, but fertility rates in the least developed countries as a group remain above 4 children per woman.

The trends with secondary education are also very clear:
Female Secondary Education and Total Fertility Rates

Of course the level of development in a country dominates and fertility rates around the world are reducing and converging. Whether this trend will continue even when all female children enjoy secondary education remains to be seen. The UK case where nearly all children do get secondary education would suggest that those with higher (university) education continue to show a declining fertility. But the real test of this hypothesis will only come when education levels around the world have equalised and fertility rates all lie around the same level.

So is the human population “dumbing down”? Not really. Education level is not intelligence. To what extent intelligence is a hereditary trait is uncertain. While it would seem that evolution should favour increasing intelligence, even this is not crystal clear. It is certainly a perception I have that “successful” people tend to be more intelligent but high intelligence does not ensure success. And success in life correlates with wealth but not so well with number of offspring.  “Success”, however we define it,  is not a genetic trait. There have been some suggestions that there may be some optimum level of intelligence for the genetic success of the species and that hunter-gatherers were actually somewhat more intelligent than we are now. Perhaps humans can be “too clever by half”!

But for some time to come, as the developing world catches up with the developed world, we can surely conclude that less-educated parents will have the higher fertility. Whatever that may mean for the long term evolution of humans, and that will be the result of the level to which we intentionally apply genetic selection.

Related: “Selection” lies in the begetting and evolution is just a result

The return of Eugenics

March 30, 2013

It is the association of the practice of Eugenics with Adolf Hitler and his Nazis and the stigma which that brings which makes it – at least overtly – politically incorrect and tabu. But it was formally practiced by many governments through the 1900’s and as late as 1975 in Sweden.  But Hitler was also a vegetarian, a teetotaler and a non-smoker. So something more than a “Hitler connection” is needed when discussing eugenics. This recent tweet from Richard Dawkins  together with all the recent developments in genetics and IVF and pre-natal screening got me to wondering as to why there is a perception in some quarters that eugenics is “evil”.

Richard Dawkins@RichardDawkins  “Eugenics”: What’s wrong with a nonrandom choice of a gene your child COULD have got from you at random, anyway, by normal genetic lottery? 9:18 AM – 17 Mar 13

Definition oeugenicsnoun [treated as singular]

the science of improving a population by controlled breeding to increase the occurrence of desirable heritable characteristics.

The application of eugenics included genetic screening, birth control, promoting differential birth rates, marriage restrictions, segregation, compulsory sterilization, forced abortions or forced pregnancies and genocide. But the history of the practice of eugenics goes back to infanticide in pre-historic times and we apply it every day without any objections in the management of domestic and wild animals. In the days when we were hunter gatherers – it is thought – infanticide was commonly prevalent:

Joseph Birdsell believed that infanticide rates in prehistoric times were between 15% and 50% of the total number of births, while Laila Williamson estimated a lower rate ranging from 15% to 20%. Both anthropologists believed that these high rates of infanticide persisted until the development of agriculture during the Neolithic Revolution. Comparative anthropologists have calculated that 50% of female newborn babies were killed by their parents during the Paleolithic era. Decapitated skeletons of hominid children have been found with evidence of cannibalism.

The Hitler and the Nazi connotation is certainly part of it but is it primarily the application of coercive measures which today gives eugenics its unsavoury reputation? As practiced in the early 20th century eugenics was applied to humans pretty much as it was for animals – effectively by promoting certain types of matings, preventing others and culling unwanted individuals. I suspect that it is not just the Hitler connection and the coercive treatment of humans which is so objectionable but also that groups of humans were treated en masse as animals for the sake of improvement of the herd.

In today’s world it is perfectly acceptable for couples using IVF to choose – so far as is possible – desirable genetic characteristics of the sperm or egg donor or both. Genetic pre-natal screening can and does lead to abortions if certain criteria are met or others are found wanting. It is effectively culling before birth. Potential surrogate mothers are genetically screened before selection. Genocide and mass rape still take place in conflict situations (Kosovo, Rwanda…) but are universally condemned. We find it perfectly acceptable however that these choices be made by individuals or couples about “their” child. It is taken to be a proper expression of individual rights – though the consequences are mainly borne by the child yet to be born (or not born). But we would find it quite unacceptable today if any government or society would impose these choices on any individual.

It would seem therefore that eugenics is here to stay. As a preventative health measure it is already acceptable if practiced voluntarily by the individuals involved. Selective breeding practiced voluntarily by individuals is also acceptable but is unacceptable if imposed by coercive decree. Enforced sterilisation of those considered mentally or physically defective was a major part of the Eugenics programs in Europe and the US and Australia but the sterilisation of the mentally ill is much rarer now. It seems inevitable that as physical or behavioural or mental characteristics can be connected to specific genes or groups of genes that these characteristics will become part of the criteria for selecting sperm or eggs or for continuing with a pregnancy or not. And even if “voluntary” individual eugenics is already in place today, I am afraid that it is not unthinkable that governments and societies will once again insist on specifying the criteria to be used to improve the common condition. I conclude therefore that it cannot be eugenics which is evil but it is the manner in which it is practiced which can.

Fighting against species extinction is to deny evolution

February 27, 2013

I was reading an article today about the threat of extinction for leather-backed turtles and once again I started wondering as to why extinction of a species or a language or of an isolated tribe arouses moral outrage or is an emotional matter for so many people. I don’t want these turtles to become extinct just as I don’t want tigers or polar bears or pandas to become extinct. But this is purely an emotional reaction because each of these animals is attractive – to my human eye – in its own right. Outside of TV documentaries, zoos and safari parks I have never seen any of them. I don’t have the same reaction when I read that guinea worms or disease-carrying species of mosquitoes are being eradicated. “Good riddance” is then the predominating feeling that I have. Yet whether a mammal or a bacterium becomes extinct the genetic loss is about the same. That dinosaurs became extinct millions of years ago or even that humans killed off the dodo or the thylacine or the Javan tiger in more recent times arouses some feelings of regret but not any moral outrage or much emotional response from me. The article about the turtles – like most other articles about the extinction of species  – is permeated with the politically correct assumption that extinction would be a “bad thing”. But I never see properly addressed the question as to why the extinction of a species is a “bad thing”.

This is essentially a value-judgement and is taken for granted and yet – in the rational plane – I can only conclude that there is nothing “unnatural” about this. In fact it is this emotional desire that species considered “attractive” should not become extinct when their time is due that is irrational. Normal or natural evolution is always a result of change. It is the result of species responding to change where the individuals of a species most suited to the changed circumstances continue and reproduce. Where the variety existing within a species is insufficient to provide any individuals who can survive and reproduce in the changed environment, the species dies out. It is said that about 90% of all species that have ever lived have become extinct. If they had not there would be no room for the 10% that exist today. Just as homo sapiens would never have evolved without the environmental changes which led to the extinction of the dinosaurs, most of the species alive today would not have succeeded their extinct ancestors if conditions had not led to their extinction. Where a species cannot compete with another – in whatever the prevailing circumstances – it dies out. It makes room for the more successful species.

Siberian Tiger Français : Tigre de sibérie Ita...

Siberian Tiger Français : (Photo credit: Wikipedia)

So what then is the objection to – say – tigers becoming extinct which is not just an emotional reaction to the disappearance of a magnificent but anachronistic creature?  The bio-diversity argument is not very convincing and is of little relevance. To artificially keep an unsuccessful species alive in a specially protected environment has no genetic value. It increases the mis-match between the existing environment and the genetic profile needed to survive in that environment. In fact the biodiversity argument is only relevant for “life” in general and never for any particular species or group of species.  It can serve to maintain a very wide range of genetic material in the event of a catastrophe such that some form of life has a chance of continuing. But given a particular environment biodiversity in itself is of little value.

Returning to the tiger as an example, the variety of individuals within the tiger population does not provide any which have the characteristics necessary for adapting to the reality of co-existing with humans in some form of urban living. Foxes, on the other hand, are evolving within our lifetimes. In a few more fox generations, urban foxes will out-compete their “wild” cousins who may well become extinct. But urban foxes will thrive. Many bird species and insects are throwing up the individuals to succeed in the shadow of the success of the human species. Bacteria and no doubt viruses are also throwing up their survivors. Some bacteria are changing faster than we would like. The polar bears who visit Churchill every year are evolving. Those who know how to forage in human communities have a distinct advantage over their less intelligent brethren. And of those who visit Churchill it is the ones who avoid attacking humans which have the best chance of surviving. (Polar bears are of course thriving and are in no danger of extinction – but that is another story). Langur and rhesus monkey troops in Delhi are in the process of becoming urbanised and “evolving” to succeed in their human-filled environment. These species are not domesticated. They are still wild but they are evolving – by selection – into new species suited to their new environment.

All those species which succeed into the future will be those which continue to “evolve” and have the characteristics necessary to thrive within the world as it is being shaped and changed by the most successful species that ever lived (though we cannot be sure how far some particular species of dinosaur may have advanced). Putting a tiger into a zoo or a “protected” environment actually only preserves the tiger in an “unsuccessful” form in an artificial environment. Does this really count as “saving the species”? We might be of more use to the future of the tiger species if we intentionally bred them to find a new space in a changed world  – perhaps as urban tigers which can co-exist with man.

If a polar bear were to hunt and kill a seal – even if it was the last individual of a seal species – it could be a matter of some regret but it would not generate any moral outrage. And then if the polar bears did not themselves adapt to find alternative food sources – then they too would fail to survive. The loss of a species can always be a matter of some regret but so is the death of any individual. Both are equally inevitable but the regret is mitigated by what comes after.

The thought occurs to me that while there is no doubt that human activity is altering the environment for many species, it is of little benefit to try and deny evolution. Species protection must consist of helping “threatened species”  to evolve and not in standing-still in some artificial environment.

Perhaps the answer is – for example – to breed and train a new species of Siberian tiger to manage vast reindeer herds where they could also be allowed to hunt and devour a few!

Junkies versus Non-junkies: Junk genes are not junk — or maybe they are

February 24, 2013

Myopic “scientists” bitching about each other is always interesting. Scientific theories have their own evolutionary life as some wither and die and some – gradually – become accepted and “proven”.  But it is the behaviour of the protagonists of rival theories which is entirely human. Rivalry, back-biting and childish insults in the world of evolutionary biology between junk-gene supporters and junk-gene debunkers are now getting entertaining.

Animation of the structure of a section of DNA...

from wikipedia

In September last year the ENCODE Project made a major splash when they published some 30 papers in front-line journals showing that most of the human genome dismissed earlier as as “junk genes”  did in fact show biological activity and probably had some as yet unknown function. They reported that they had transcribed some 76% of “junk” DNA and that more than 50% of all genes could be accessible to proteins which can control genetic behaviour and they concluded that over 80% of human DNA serves some purpose.

The term “non-coding” DNA, then popularised as”junk” genes, was coined in 1972. This idea  gradually gained favour and by 2003 the human genome was supposed to consist of some  26,000 protein-coding genes within a large amount of non-coding DNA where the non-coding or “junk” DNA represented some 98% of the whole genome. The results of the ENCODE project turned this idea on its head. The junk gene supporters were not amused. It has taken them a little while to circle the wagons and formulate a response to the flood of papers published in September. And the response resorts to unusually harsh language for scientific discourse. It would seem that the “junk” gene protagonists have been prodded in their vitals and feel their life-work and their livelihoods being threatened!

Junkies versus Non-junkies! The battle-lines have been drawn. They have now published an open-access diatribe: On the immortality of television sets: “function” in the human genome according to the evolution-free gospel of ENCODE

The Guardian: “Everything that Encode claims is wrong. Their statistics are horrible, for a start,” the lead author of the paper, Professor Dan Graur, of Houston University, Texas, told the Observer. “This is not the work of scientists. This is the work of a group of badly trained technicians.”

Scientists are being called technicians — no less!

The junkies write:

From an evolutionary viewpoint, a function can be assigned to a DNA sequence if and only if it is possible to destroy it. All functional entities in the universe can be rendered nonfunctional by the ravages of time, entropy, mutation, and what have you. Unless a genomic functionality is actively protected by selection, it will accumulate deleterious mutations and will cease to be functional. The absurd alternative, which unfortunately was adopted by ENCODE, is to assume that no deleterious mutations can ever occur in the regions they have deemed to be functional. Such an assumption is akin to claiming that a television set left on and unattended will still be in working condition after a million years because no natural events, such as rust, erosion, static electricity, and earthquakes can affect it. The convoluted rationale for the decision to discard evolutionary conservation and constraint as the arbiters of functionality put forward by a lead ENCODE author (Stamatoyannopoulos 2012) is groundless and self-serving.

Would the Junkies  – I wonder – allow 98% of their DNA – or that of their children – to be excised if it could be?

“Selection” lies in the begetting and evolution is just a result

November 19, 2012

Recently I posted about two  papers by Gerald Crabtree who suggested that perhaps human intelligence peaked as hunter-gatherers, and

“that we are losing our intellectual and emotional capabilities because the intricate web of genes endowing us with our brain power is particularly susceptible to mutations and that these mutations are not being selected against in our modern society”.

Apparently it is not politically correct to suggest that humanity might be on a “degenerative” evolutionary path for intelligence and Crabtree’s speculations have been the subject of indignant criticism:

Why Gerald Crabtree’s speculations about declining human intelligence are wrong: ….  But like Sanford, Crabtree fails to analyse the problem correctly. In particular, neither show any understanding of quantitative genetics (this is the area of genetics that deals with lots of genes acting on a trait). But unlike young earth creationist Sanford, Crabtree doesn’t even bother to present any data to indicate that an intellectual decline has actually happened.

Discussions and arguments about “intelligence and race” or the “future evolution of intelligence”  or “what intelligence is” or whether “intelligence is selected by natural selection” are fascinating but – in evolutionary terms – are largely irrelevant. Evolution is not a force of change. It is the consequences of a response to change, a result – a report-card of what has happened before.

What counts for evolution – both for what has happened before and for what will happen in the future –  is which inheritable traits lead to the most begetting. It is in the begetting of offspring that all “selection” lies. This applies both with natural and with artificial selection. All other traits which happen to be present in the individual organisms being reproduced and which are inheritable are only carried along with the ride.

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