You can look at it like pure coincidence if you'd like, but its evolution. I won't claim to know if our opposable thumbs came before or after we scurried up the trees.. but once that mutation happened, it increased the survivability of our ancestors. And you could look at the trees as the reason our thumbs evolved how they did, but it happened through chance. Life likes to fill niches, and in order to do that it needs to evolve into that niche. If a new niche opened up, the traits needed to fill needed to mutate. Since its random, a thousand different traits could mutate and not be the ones needed to fill the niche.. waiting til the right mutation comes along. Its similar to how we came down from the trees too. Our digits started to mutate to be shorter, to the point where our feet could no longer operate like our hands, gripping branches and such. Thing is, in order for that trait to take off, the niche of the ground needed to free up. Our ancestors were forced to stay in the trees due to big predators and if one mutated to where it couldn't stay in the trees, it got eaten. Once the ground started to free up, that mutation would of been beneficial and carried on. If it weren't for trees, I highly doubt that we'd ever have evolved our thumbs.. and without that, our hands wouldn't be what they are.. but I wouldn't say trees were the reason for their evolution, just that their existence allowed it to happen through chance. Mobile mumbling..
Competition. It's pretty solid through most species, but as they evolve their ancestors that they evolved from would be competition. It's not until they evolve even more to where they're no longer at odds with each other that they have a chance of not competing for the same things. We didn't need to kill off monkeys and apes as they stayed in the trees, but any other relatives that were similar to us, like neanderthals, were competition for resources outside the forests. It doesn't even need to happen through force either. Even if we tried to reach a balance with an evolutionary cousin, being better suited means we could gather our resources better, leaving nothing for them to survive on. Mobile mumbling..
I won't claim to know if our opposable thumbs came before or after we scurried up the trees.. but once that mutation happened, it increased the survivability of our ancestors. So once our ancestors began to spend more of their time around trees, there were a select pool of them that then grew opposable thumbs..? If this is the case, then it does imply that because there was more than just one of our ancestors that ''randomly'' mutated a thumb at this time, that there was a reason that drove their mutation to occur, that is that the habitat in which they lived required them to grow thumbs so that they may manoeuvre etc more easily on and around the trees. If a new niche opened up, the traits needed to fill needed to mutate. This answers my question I think, that is that the mutations are not entirely ''random'', but the circumstances that require the mutations to occur, are.
The problem is that humans are trashing the earth at far too rapid of a pace for evolution to keep up. Evolution is a gradual process over thousands of years. Our environment is changing too rapidly for many species to keep up.
If humans evolved from fish, how would lungs evolve from gills than? Sent from my Galaxy Nexus using Grasscity Forum mobile app
It only really takes one mutation that is beneficial. If only one of our ancestors mutated and it proved to be successful, they would of passed that trait along. Then their offspring would have a chance at gaining that mutation. Say the first evolved and passed it along, they could of had 30 offspring and only 3 had the beneficial mutation, or even just one.. but the ones that don't have the mutation still have it in their DNA and are able to pass it along. The trait might only surface a few times in several generations, but its in the gene pool. As it continues to surface, it'll appear more and more due to its benefit until one day it becomes a permanent part of the species. If you're looking for a reason that isn't random, I'd say that reason would be the species itself.. cashing in on a chance event. Life isn't dumb and when a species gains a beneficial trait, it uses it the best it can. That would be something difficult to explain on mobile without links and such to provide, but look at fish, then look at amphibious fish, then amphibians. As fish started to walk on land, they couldn't go very far.. but if one of those fish mutated to where it could stay out of the water a lil longer, it would prove beneficial and pass it along. That trait would then evolve more and more. Look at mud skippers and lung fish.. while looking at fish and amphibians to get a good idea of how life crossed the bridge from water to land. Mobile mumbling..
evolution need not always be beneficial either. some of it is just dumb luck that your species happened to survive.
This is what I had difficulty with understanding - so, each and every human alive today, may have descended from that one ancestor in particular that grew opposable thumbs?
not necessarily. it couldve happened that two or more different lines followed a common path that was able to breed which produced humans as well. there couldve been thumbs and non thumbed humans, and the non thumbs eventually die out. when it comes to evolution it can be easiest not to think of animals as being different species. were all multiple celled organisms that went down different paths. eventually our mutations make us different enough to not be able to breed with another line of evolution, giving rise to species.
Yes, but say that there was only one that evolved opposable thumbs, it would follow that every human alive today would of descended from that one ancestor in particular, because the other's did not evolve, and thus were later killed or remained as simpler animals.
I think we're evolving every day. Evolution doesn't just happen, it's a very slow, progressive thing. ... Unless we're all pokemon. Then we just have to kill other people until we suddenly transform.
I can't claim that there was only one, but its possible as it really only takes one to get those traits into the gene pool. It's even possible that more evolved convergently.. like one mutated and evolved and started to spread, but another evolved independently in a different location and/or time with the same results. But I would wager that it was only one that got the ball rolling on the trait, cause that's usually how it happens. Once that beneficial trait pops up, its going to keep going as long as its beneficial. The number who have the trait would grow exponentially generation after generation.. from 1 to maybe 3 to 8 to 19 to 50 to 138 to 400 until that trait spreads throughout the entire species and once it gets a good foothold, those without the trait are usually screwed as they're still competing with their advanced evolutionary offspring. Mobile mumbling..
nah man. two non thumbs can produce a thumb, thats kinda the whole point. the mutation can happen independently many times. although i would argue that if you take it back far enough, all multiple celled organisms probably come from the first multiple celled organism. however its not like there can be a ton of certainty in such matters. it could have happened that one thumb led the way.
You're thinking too small. This happened over millions of generations. It's like trying to figure out who the first asian person was.
Ah, yes, that very convenient conjecture of a "random" mutation is the gap in which darwinists weasel their way out of manifestly revealing their humbugs. That's a very important... "but"... that "but" is what the whole debate revolves around... and, as far as I'm concerned, darwinists are outright begging (and lantely skipping over) the question.
ive always viewed evolution as being much more about eliminating the shitty traits that got you killed and less about gaining an advantage among your peers. coupled with a lot of luck. in all that time surely there was some mutation that truly stood alone as better among all other life forms......and then a hurricane or a volcano or something ruined its shot at reproduction. but.....what say you of the many animals who live in water but surface for air?