[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]
2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

View post   
File: 419 KB, 691x2052, COLOR THEORY.jpg [View same] [iqdb] [saucenao] [google]
5575206 No.5575206 [Reply] [Original]

Why have horseshoe crabs never evolved?

And don't say that they don't need to because things will always evolve as long as there are mutations.

>> No.5575215

>>5575206
citation needed

>> No.5575224

>>5575215

horseshoe crabs have been around for 450 million years and they haven't evolved into another kind of species. Google it.

>> No.5575227 [DELETED] 

>>5575206
if it's suited to its environment, it doesnt need to change to survive
http://en.wikipedia.org/wiki/Living_fossil

lern-2-zoology

>> No.5575229

>>5575227

>it doesnt need to change to survive
That's not valid argument. Evolution happens whether the organism wants to evolve or not.

>> No.5575238 [DELETED] 

>>5575229
nope
if it's suited to it's environment, theres no evolutionary requirement to change form

animals evolve to be suited to their environment
so if they reach an optimum (even a temporary optimum, for a while)
then they're gonna stay static.

organisms that mutate don't fare any better, because the current form is already at an optimum, so they have lower reproduction success, and the superior form still outcompetes them.

>> No.5575237

>>5575229
who said the horseshoe crab wanted to? maybe it doesn't NEED to evolve as it's already perfectly suited to its environment...and maybe it's mutations aren't as visible as we think they are, just like sharper feet, harder shell, better eyes, but no real change just "stat boosting"

>> No.5575240

>>5575229
That's not true, you misunderstand a fundamental premise of evolution. Evolution is dependent on environment.

>> No.5575245

>>5575240

I thought Evolution was dependent on mutations.

>> No.5575260

It is quite an assumption to say that horseshoe crabs have not evolved at all, even a slight change or two still counts as evolution.

Who's to say they have or they haven't?

In any case, selective pressures seem to have remained rather constant over time.

Also, mutations that lead to evolution are quite rare. More often then not mutations are deleterious.

>> No.5575278 [DELETED] 
File: 127 KB, 754x709, then_than.jpg [View same] [iqdb] [saucenao] [google]
5575278

>>5575260
>mutations that lead to evolution are quite rare.
>oh_shit_nigger_wat_r_u_doing.jpg

all mutations ARE evolution in action.
evolution doesnt have a set path or goal, it doesnt necessarily add complexity. in some cases it can even move 'backwards' to what humans would consider to be 'progress'

>More often then not mutations are deleterious
actually, most are neutral
>more often then not
>then
twat!
<<<

>> No.5575283

>>5575245
Yeah but if a lemur is born with a mutation that causes its dick to fall off it's not going to reproduce, will it?

>> No.5575299

>>5575245
Mutation is one mechanism by which evolution occurs, but it isn't the force which brings about a diversity of life on earth. These are rather crude terms, I am doing some real injustice to some published work here.

Mutations must have some kind of advantageous relation to environment in order to proliferate. Conversely, if environment changes drastically, this will make major changes in terms of the distribution of certain organisms and traits in a given biome/climate/etc.

>> No.5575315

>>5575206
HEY OP, I'm doing a project about color theory. Where exactly did you get this picture? The website listed doesn't exist anymore and I can't find it on the new one.

>> No.5575321

>>5575315

I got it from /b/....

>> No.5575323

>>5575278

You do realize that mutations are like the lowest on the totem pole when it comes to actual contributions towards evolution? The environment and competition have a much greater net effect on differentiation than mutation does.

Perhaps I should have been more clear in my description of mutations, I was considering mutations that can actually be observed in the phenotype. Such as albinism, which is a mutation that is clearly selected against when it does occur. It is not often that a mutation arises that actually leads to better fitness, except for perhaps in singled celled organisms and viruses.

>> No.5575335 [DELETED] 

>>5575323
you need both.

without mutation, theres no mechanism to facilitate change in the organisms
without changes in environment, or aspects of competition, there is no driving force to pressure certain mutations to thrive rather than others.

>> No.5575350

>>5575321
Hell.

>> No.5575359

>>5575335

I guess maybe I'm thinking too much on a ecological scale of evolution, since that is my field of study. In terms of ecology, mutation as mechanism of change takes over too long of period of time.

>> No.5575369 [DELETED] 
File: 77 KB, 458x604, JqV3e.jpg [View same] [iqdb] [saucenao] [google]
5575369

>>5575359
depends on the organism
it's faster on those with a high mutation rate and/or small amount of time between generations. (bacteria, etc)

thats why it can take millions of years for complex species to evolve a pair of wings, but e-coli can potentially evolve resistance to a new antibiotic in just a few years.

what are you studying?
how old?
plans for the future?

>> No.5575381
File: 419 KB, 1024x676, view from mt marcy.jpg [View same] [iqdb] [saucenao] [google]
5575381

>>5575369

No yeah I totally understand that.

Studying Ecology and the like.
I'm 20.
Probably gonna get my Masters and then go work for a government environmental agency, USGS, Forest Service, etc. Then probably get my PhD later. But I have been giving some thought lately about joining the Peace Corps. or taking a semester off to thru-hike the AT.

>> No.5575481

>/sci keeps saying that biology is not a science
>half the niggers here can't understand the simplest concepts of evolution.
First, evolution rarely occurs due to significant mutantions over a course of a few generations, instead being influenced by characteristics that may be quite common to the species, but then when those with that characteristic have an advantage due to enviromental conditions for example, they generate more offspring, and the members of the species with that characteristic will increase.
but it's not that simple in the cellular level. when you select one characteristic, many others "follow" it through the generations, since genes are not independent structures on themselves (take for example dog breeds, whom selection for certain characteristics led to serious health problems in some races, because other characteristics came together when selecting a certain type).
and second, just because the appearance and external morphology of a species has not changed in the course of millions of years, it doesn't mean his metabolism, internal and cell structute hasn't. take the Coelacanth for example, oftenly called a "living fossil", since his appearence is virtually the same as it was about 360 million years ago. but that doesn't necessarily mean that he is exactly the same as then, especially because 360 million years is a hell lot of a time for enviromental changes to ocurr. In any case, if we could look at the internal structure of the horseshoe crab at about 400 million years and now, you can bet it would probably be very different in its internal structure.