Why is it that two different species of animals can't mate?

Question

I really don't know the scientific answer to that one. A horse and a tiger let's say. Why can't they produce offspring? Scientifically speaking?

Answer 1

There are lots of reproductive barriers between species.
Prezygotic barriers (before breeding)
Behavioral isolation--Mating rituals are different
Habitat isolation--species don't encounter each other
Gametic isolation--Gametes (sperm and egg) incompatible
Temporal isolation--different breeding seasons
Mechanical isolation--The parts don't fit together
Postzygotic (after breeding)
Hybrid inviability--zygote is formed but it aborts
Hybrid sterility--offspring is steril (mule)

Hope this is helpful

Answer 2

There are alot of physiological reasons, which we won't go into here. But the most prominent reason would be genetics. When the egg and the sperm meet, meiosis must occur to promote development of the fetus. However, when two different species mate, there are complications in the pairing of chromosomes. You must note that not all species carry a diploid genome, there euploidy and even aneuploidy are quite common. So, a triploid individual cannot mate with a tetraploid because there will be complications in segregation. So, chromosomal nondisjunction is a major reason as to why two species are highly unlikely to produce a viable offspring.

Answer 3

Technically, they can mate, they just can't always reproduce. If they're closely related, like lions and tigers (ligers/tigons) or donkeys and horses (mules/ginnys), you can get viable offspring that are usually infertile. It all has to do with compatible DNA.

Of course, I've always wanted to crossbreed St. Bernards with Chihuahuas. Can you imagine that litter?!! They're both dogs, so it should work.

Answer 4

They can mate, but usually they can't reproduce. Unless the genetic structure is fairly similar (horse and donkey, for example), the chromosomes won't suitably match up and generate cells that can subsequently reproduce.

Answer 5

Usually they have different #'s of chromosomes and even if they do, the animals have differenent chromosome patterns. This means the chromsomes from one animla can't join up with the chromosomes of the other animal.

Answer 6

Their DNA is too different, rendering it incompatible. The resulting mix of DNA cannot create a functioning organism.

Answer 7

Wouldn't it be amazing if they could?

Elephants that fly. Donkeys that talk.

Sharks that could walk on land, knock on your door, run for public office....oh wait....I guess it is possible.

Answer 8

cAUSE their dna is different. and the things arent in the right places.σ ν

Answer 9

Their DNA is way too different.

Answer 10

its all in the genes
or it isnt