This is such a weird to put eugenics. Say I kill all blue eyed people, would you then say "People are evolving brown eyes due to this guy" ?
Female African elephants are evolving without tusks due to ivory poaching
221–230 of 320 posts
Re: Female African elephants are evolving without tusks due to ivory poaching
#222This is such a weird to put eugenics. Say I kill all blue eyed people, would you then say "People are evolving brown eyes due to this guy" ?
It's not a consequence intended by ivory poachers.
Re: Female African elephants are evolving without tusks due to ivory poaching
#223Earlier quoted context omitted.
Is anyone else surprised at how quick species can seem to evolve in these kinds of ways? Asian and African elephants are supposed to have separated millions of years ago, yet still strongly resemble one another. Yet in a few decades, something as fundamental as the presence of their tusks can shift dramatically. And that in a species with very long gaps between generations. It makes me suspect there's something else…
A point evolution event can happen extremely rapidly if there's a clearly selective mortality event. If a new predator is introduced to a population that selectively kills only certain traits, that mutation can become dominant in the population within just one or two generations. Imagine if aliens came to Earth and killed everyone over 5'6" tall. That "evolution" would be essentially instantaneous.
That evolution would still take multiple generations, since a 5'5 father and a 5'5 mother will have a 5'8 son on average.
Re: Female African elephants are evolving without tusks due to ivory poaching
#224Earlier quoted context omitted.
Evolution IS selective breeding. The members of a species most fit for their environment are successful in procreation. The female elephants without tusks are surviving at higher rates which is resulting in more offspring with no tusks. This causes a shift in the population where a trait previously with no or little benefit becomes advantageous and the shift in genetic makeup of the whole population evolves.
But we don't commonly run around saying Arabians and Morgans are different because of evolution. Neither do we say that chihuahua's and labradors have evolved into their present form. In my humble opinion "evolution" refers to speciation, which takes very many generations.
The distinction between one species and another is pretty arbitrary in many cases. Exact species boundaries, or even the concept of "species" itself, are something humans determine, by convention. Evolution is something that happens regardless.
> Evolution is defined as the change in the inherited traits of a population of organisms through successive generations… When particular genetic sequences change in a population (e.g., via mutation) and these changes are inherited across successive generations, this is the stuff of evolution… One can distinguish between two general classes of evolutionary change: microevolution (change below the level of the species) and macroevolution (change above the level of the species)… These [micro-evolutionary] processes can, but do not necessarily, lead to the formation of new species over time but instead result in fluctuating frequencies of traits within populations tracking ever-changing selective pressures.
https://www.nature.com/scitable/knowledge/library/evolution-...
Re: Female African elephants are evolving without tusks due to ivory poaching
#225While sad as a whole, the responsiveness of evolution is beautiful in this case. It also demonstrates that human efforts to stop poaching have not been successful (otherwise this evolution wouldn’t happen), but luckily, nature responds.
Its important to realize what this "response" actually is. Nature isn't actively doing anything. You have 100 elephants, maybe 5 are typically born without tusks. Suddenly you kill the other 95 for their tusks, leaving behind those 5 to survive and reproduce and next generation, 33 of your 100 elephants are without tusks or something like that. Over time, humans are acting as a predator in the environment, driving a…
I mean, "nature" never "actively" does anything, there is no active entity that is "nature". It's a metaphor, in all cases.
Re: Female African elephants are evolving without tusks due to ivory poaching
#226Honest question from someone who knows virtually nothing about chemistry or material science: is there a difference in quality between synthetic and natural ivory? If not, why is poaching even still a viable market?
Ultimately, a good number of people will want "the real thing", even if it is virtually identical. There are plenty of people who think lab grown diamonds are illegitimate, despite having the exact same chemical composition as mined diamonds. For the rich and powerful, the Ivory is more important as a status symbol than anything else. Synthetic Ivory is effectively useless as a signal. Plus, there are people out ther…
Synthetic ivory is great as a signal if it's indistinguishable and you lie about it's origins.
But a lot of people want to/need-to "signal themselves".
Which reminds me, I'm not sure why cops don't try to move fake ivory into black markets, have sting operations where once they catch a dealer, instead of arresting them, force them to sell their fake ivory, undercut the market enough that poachers have incentive.
Probably China isn't that concerned about the problem.
Re: Female African elephants are evolving without tusks due to ivory poaching
#227Earlier quoted context omitted.
Maybe not as much as you would think. Naturally, not all males mate and the mating ratio is not always 1:1. Take humans for example, it's been shown our ancestors comprise mostly of females in a ratio roughly 3:2 to males. That is, some male ancestor probably mated with more than one female ancestor somewhere.
>our ancestors comprise mostly of females in a ratio roughly 3:2 to males. For anyone else wondering how this is possible on an individual level, apparently a lot of people used to reproduce with their first and second cousins.
Still not that uncommon in few parts of the world.
Re: Female African elephants are evolving without tusks due to ivory poaching
#228Earlier quoted context omitted.
Not only is it more advantageous, it actually was force selected for (IIRC, poached elephants are often left for dead). So this is closer to selective breeding/artificial selection more so than natural selection.
What's the difference in this case? Doesn't seem too different from how camouflaged eggs would have developed (maybe just faster because the selection mechanism is so strong). When I think of selective breeding I think of humans picking out which animals (cows/dogs/wheat/etc) get to reproduce.
Right, selective breeding is just a subset of natural selection. Not sure why folks seem to want to exclude humans from nature, like we’re not part of the exact same system.
Re: Female African elephants are evolving without tusks due to ivory poaching
#229Re: Female African elephants are evolving without tusks due to ivory poaching
#230Earlier quoted context omitted.
Seems like the mutation kills male embryos. https://www.science.org/doi/10.1126/science.abe7389 > Survey data revealed tusk-inheritance patterns consistent with an X chromosome–linked dominant, male-lethal trait. Whole-genome scans implicated two candidate genes with known roles in mammalian tooth development (AMELX and MEP1a), including the formation of enamel, dentin, cementum, and the periodontium. One of these lo…
Why is it possible for us to have a 50:50 gender ratio? Why haven't mothers that only give birth to girls taken over the world? Do unpaired girls really die that quickly?
Humans have near but exactly 1:1 ( 1.05-1.07 favoring males at birth ). Fisher's principle[1] explains why this 1:1 is common.
There is big imbalance problem for humans as well, many cultures prefer male children over females, the two largest countries - India and China have big imbalance for different reasons there is estimated 100 million less girls than boys in these two countries alone as result of sex selection/ infanticide etc .