Monday, April 19, 2021

Creation Moment 4/20/2021 - Giraffe Genes

And God said, Let the earth bring forth the living creature after his kind,...
Genesis 1:24
 
"When evolutionists ran divination on giraffe genes, did the visage of Darwin appear? 

Darwin thought he got the best of Lamarck by using his new ‘natural selection’ hypothesis to explain the giraffe's long neck. 
It’s a story all high school biology students learn: Lamarck incorrectly thought that the necks became longer as giraffes stretched for the treetops. Their offspring inherited those acquired characteristics. Student’s hear that August Weismann proved Lamarck’s theory wrong by chopping off the tails of generations of mice; this demonstrated, textbooks all teach, that animals do not inherit acquired characteristics.

Then, with pomp and triumph, Darwin’s superior theory of natural selection is introduced: giraffes are tall because chance variations enabled some to reach the treetops. These survived and the short giraffes died out. The genes of the lucky giraffes were passed on to their baby giraffes. (How the young giraffes, not yet tall enough, survived starvation is not included in the story, but Charlie Darwin is congratulated anyway as the most original thinker in the history of science.)
 
Lamarck and Darwin both believed that the giraffe evolved from some pre-giraffe with a short neck. What if giraffes, instead, were always tall? That seems reasonable unless one starts with the assumption that all animals have evolved from bacteria ancestors and grew to be what they are.

Now, a new complete giraffe genome can help settle the issue. Published 17 March 2021 by Liu et al. in Science Advances (open access), it gives biologists a fresh start at connecting genes to traits for this iconic mammal.

The suite of adaptations associated with the extreme stature of the giraffe has long interested biologists and physiologists. By generating a high-quality chromosome-level giraffe genome and a comprehensive comparison with other ruminant genomes, we identified a robust catalog of giraffe-specific mutations. These are primarily related to cardiovascular, bone growth, vision, hearing, and circadian functions.

What? No genes directly accounting for long necks?

The very trait that most interests everyone is never mentioned in most summaries of the paper, including those in

  • Science magazine – no mention of evolution or natural selection acting on mutations.
  • Copenhagen University – only speculates about “strong selection” for circadian rhythms for sleep.
  • The Scientist – only mentions blood pressure and sleep as evolutionary adaptations.
Heart and bone strength are important traits for height—a giraffe
needs a powerful heart and strong bones to stand so tall—but none of the articles explain from the genome how
giraffes evolved long necks. 
Instead, they focus their attention on one particular gene named FGFRL1. In humans and mice, this gene is associated with bone strength and with blood pressure. They tried inserting the giraffe version of this gene into mouse embryos. Guess what happened: the mice did not grow long necks. But if they had, wouldn’t that be a nice storybook that Deborah Keleman could write for the kiddies?  But since she makes up imaginary animals anyway, that fact should not stop her from writing about Miceraffes.)

A few other interesting things were found in the genome:

  • Circadian rhythm genes differ. This might account for why
    giraffes get by with little sleep (since getting up off the ground is a “lengthy and awkward procedure”).
  • Olfactory genes are reduced. The scientists speculate that smell is not as important when an animal’s nose is up at “5m compared to ground level” but that is debatable; there is a lot to smell up there, especially the leaves giraffes want to eat.
  • Eyesight gene changes might account for why giraffe vision is so sharp. The evolutionists speculate that this is an “evolutionary trade-off” for less reliance on the sense of smell. Why is natural selection unable to improve both?
  • So far, the genome does not account for many of the most obvious traits of the giraffe – the long neck, long legs, fur patterns and more." CEH