Have all species changed?

Question

Approximately what percentage of the Earth's species have changed over time?

a. 0%
b. 35%
c. 70%
d. 95%
e. 100%

I'm guessing 100% have changed. Am I right? Thanks for those who help!

Answer 1

This is not as easy a question to answer as you might think. In order to decide if a species has changed or not you need to be able to define exactly what the species is so that the idea of it having changed from what it is to something else actually makes sense.

A species is usually a very large group of individuals, who may very considerably from one to another and can persist for millions of years. An example of a species that appears to be extraordinarily diverse are dogs. Amazingly both a Chihuahua and a Great Dane are the same species by the ordinary definition that they can interbreed and produce viable offspring.

At any given point in time a species is made up of a unique group of individuals and so in a trivial sense you could say that every time a new individual is born or one dies the species has changed since the group is now slightly different. I don't think that is what you mean at though.

You probably are thinking of some more material change such as the average appearance, size, color, etc. Some of these might be considered significant others but many might not actually be significant. They could be a temporary adaptation to local conditions.

A good example is a particular type of moth that lives in England. It spends the day sleeping on the bark of birch trees and so had adapted a whitish coloration with dark streaks that mimics birch bark and so avoids being eaten by birds. Shortly after the industrial revolution the air in England became so sooty with coal smoke that most birch tree bark became stained a blackish color with white streaks. The white moths now stood out like sore thumbs and were gobbled up in great numbers by birds. Fortunately there were a few darker individuals that survived and within a fairly short time the moth's predominate color changed from whitish to blackish. After decades of really polluted air the English finally cleaned up their act and nearly eliminated coal smoke resulting in the birch trees retuning to their former whitish appearance. The moths have also reverted back to their whitish appearance as well.

So the question is: "Did the moths change as a species or not?"

Note that there had always been a few unlucky blackish moths and that there still are, but for a few decades they were that majority. I would argue that is not a significant change, but I admit it also begs the question of what would be.

Certainly there is one change that would undoubtedly be considered significant. Suppose the most modern examples of a species had changed enough that they would be unable to breed successfully with the earliest members of a species. Keeping in mind that many species persist for many millions of years that is entirely possible and even likely. It does raise an interesting problem though, and that is that there is no practical way to test it. If millions or even thousands of years separate the earliest members and the latest members of a species you will have a difficult time breeding them. ;).

I have to say after having thought about this that there is not meaningful answer to your question, which makes it a very interesting question indeed.

Answer 2

You're right about 100%. All species evolve into other forms. We all began as prokaryotes (bacteria) and became simple eukaryotes (eg yeasts) via evolution. All higher animals have evolved from thise first eukaryotes. Most species last 1-10 million years only. Life has been around 4 billion years so billions of species have come and gone.

Answer 3

If this is a christian test, the answer is a. because most christians only believe in creationism and everything that is existing is the way god made it. *cough*Bullsh*t*cough*

But in reality (the real world, not the fictitious bible world) the answer would be e. 100% because all species have had to change to adapt to their environment over time.

Answer 4

E given the right amount of time all species will change

Answer 5

a transforming into variety of analyze has been offered as info that 2 animal species can integrate to supply a 0.33, sexually conceivable species in a technique standard as hybrid speciation. Newly pointed out examples incorporate the two bugs and fish. Animals have been many times concept to adapt whilst a single species steadily splits into 2 over many generations. yet scientists now have faith that habit that has been referred to as animals' sexual errors could desire to be an significant rigidity of their evolution. Hybrid-shaped species are often extremely perplexing to come across because of the fact of their close actual resemblance to their discern species. yet right this moment scientists are waiting to gather the particular molecular documents mandatory to perceive till now unrecognized hybrids. 10 p.c. of animal species and 25 p.c. of plant species are actually standard to hybridize. often evolution happens so slowly that it may't be watched. The 4 letter code that constitutes the DNA of all residing issues alterations over the years; for example individual or a number of letters could be copied incorrectly [substitution], misplaced [deletion] or gained [insertion]. Such alterations can deliver approximately sensible and structural alterations in genes and proteins and ultimately to the formation of latest species. Insertions are plenty greater common on an identical time as deletions seem to be uncommon. yet what's your situation with evolution? the main significant christian church homes no longer purely totally settle for it yet critically criticize the creationists for screwed questioning!! The Pope, Catholic Church, Church of britain and mainstream church homes all settle for the super bang and evolution!! Lord Carey the former Archbishop of Canterbury placed it very properly – “Creationism is the fruit of a fundamentalist attitude to scripture, ignoring scholarship and severe gaining wisdom of, and perplexing different understandings of actuality”!!

Answer 6

No, if you look at certain species like the cockroach, the shark, the coelacanth, they haven't changed for countless bazillions of years; they are still the same as they were way back when!

Answer 7

Species change when it's nessasary, so "all" becomes a big word, and guessing the correct word.

Answer 8

c.or d. Not everything has changed. for example, aren't crocs , gators, and sharks, pretty much unchanged? things with small brains?

Answer 9

probably about 95 % example...cockroaches have not changed in years...

Answer 10

i dont think so. sharks are about the same, seleocanth is about the same, i likely spelled it wrong, its a fish, crocks and gators are about the same, who knows