/sci/ - Science & Math

[Faggot !Mjk4PcAe16 No.2655609]

Hello /sci/, today I tried explaining evolution to a friend who didn't quite understand it. I used the following example, can you tell me if there is anything wrong with it? My understanding in itself isn't too strong.

I gave the example of a very barren planet consisting of only two groups of animals and two food sources. Whatever evolution and planetary change was involved at getting it to this point is irrelevant, I want to keep things simple to exclude as many variables as possible.

Basically, there are two closely related species, species A and species B and two food sources, very tall, sturdy trees with fruit on them and bushes with fruit on them. Species A is generally around 2-3ft tall and species B is about 7ft tall. They can breed amongst one another, but species A generally prefers to breed amongst itself.

[Faggot !Mjk4PcAe16 No.2655610]

There are, obviously, no predators on the planet that could prey on either species, no major rivers or mountains and no major weather disruptions. It's a plain, barren planet. It is also very hard to place enough force into a tree to shake some fruit down, so the only way to get at it is to pluck it down. However, species A is too short to do so.
Anyway, both species thrive mainly off the berries. However as the population of both species grows the rate the berries are capable of growing eventually is incapable of making up for the amount eaten, and so the berry population dwindles and eventually goes extinct. Species A is left with no food source, while species B quickly takes advantage of the trees. Individually they are selfish, and only share food with their young. Over time, species A, whose only food source now are scraps and the fruit off dead trees, begins to die off. What was once a 1:1 ratio is now a 1:10 ratio in favour of species B. Now being less selective, species A begins to mate with species B. Their children range from 4-6ft, however most children less then 5ft eventually die due to scarce food. This keeps happening, with most children between 5-7ft outperforming their shorter siblings until the 3ft species is eventually extinct. There are now two main groups, those beings at 5-6ft and the dominant 7ft (pure offspring of species B, still make up most of the population).

[Faggot !Mjk4PcAe16 No.2655615]

There are, obviously, no predators on the planet that could prey on either species, no major rivers or mountains and no major weather disruptions. It's a plain, barren planet. It is also very hard to place enough force into a tree to shake some fruit down, so the only way to get at it is to pluck it down. However, species A is too short to do so.

Anyway, both species thrive mainly off the berries. However as the population of both species grows the rate the berries are capable of growing eventually is incapable of making up for the amount eaten, and so the berry population dwindles and eventually goes extinct. Species A is left with no food source, while species B quickly takes advantage of the trees. Individually they are selfish, and only share food with their young. Over time, species A, whose only food source now are scraps and the fruit off dead trees, begins to die off. What was once a 1:1 ratio is now a 1:10 ratio in favour of species B. Now being less selective, species A begins to mate with species B. Their children range from 4-6ft, however most children less then 5ft eventually die due to scarce food. This keeps happening, with most children between 5-7ft outperforming their shorter siblings until the 3ft species is eventually extinct. There are now two main groups, those beings at 5-6ft and the dominant 7ft (pure offspring of species B, still make up most of the population).

[Faggot !Mjk4PcAe16 No.2655618]

Now over time, the trees begin to be too little to support either species. An advantage, however, is given to the 5-6ft species who require less food due to their shorter size, but both species have equal access to food. Species B dies off at a quicker rate as it is less able to support its population. Eventually, the 5-6ft species is now outnumbering the 7ft species.

From that we've had an example of extinction occurring, and showing how one species can eventually rise to become the dominant species when it was once the smaller species. Are there any major problems with it?

[Anonymous No.2655643]

Evolution works by mutations in development.

Where the fuck did you pull that shit?

[Anonymous No.2655659]

>>2655643

[Anonymous No.2655681]

>>2655643
He just described.. fuck sakes
3/10

OP, it sounds good to me if you're just explaining simple concepts, but there are many other things that contribute to evolution as well, besides survival of the fittest. You ought to read up on it yourself.

[Anonymous No.2655689]

different species can't breed to give fertile offspring, thats the definition of species

[Anonymous No.2655692]

>>2655689
This. It would be better if you described them as tribes, but apart from that it's quite good for a basic overview.

[Anonymous No.2655704]

>>2655689

tell that to a plan biologist

[Anonymous No.2655708]

>>2655704

*plant

[Scientist No.2655712]

>>2655609
>They can breed amongst one another, but species A generally prefers to breed amongst itself.
There's one problem. It's not evident that you have separate species if they're interbreeding.

Speciation happens when there is a separation of populations of a previously single population of a single species. Usually a geographic separation. Then, because evolution isn't determinalistic, and there is no "best" in evolution, the now separated populations will evolve own their own separate paths, becoming separate species no longer able to interbreed.

[Faggot !Mjk4PcAe16 No.2655733]

So tribes would be a better choice of word?

[Faggot !Mjk4PcAe16 No.2655756]

If your friend doesn't beleive in evoltulation smake him upside the head

[Faggot !Mjk4PcAe16 No.2655762]

>>2655756
Not me.

[Faggot !Mjk4PcAe16 No.2655766]

OP's trip is #2

Don't pick such a fucking easy one too guess.

[Anonymous No.2655782]

Tell him about penicillin resistant bacteria Ie. MRSA in the body. When antibiotics are introduced to the environment (in this case the infected person), competition is killed and the MRSA colonises the area and out competes the less suited microbes. Or I find explaining the basic principles on a microbial level is easier than explaining it in a multicellular organism context.

[Anonymous No.2655802]

>>2655782
The subject is evolution, not medicine.