Living Evolutionary intermediates?

Question

i know there are quite a few intermediate fossils when it comes to evolution.
however are there any intermediates that are still alive today? besides the example below.
example the legless lizard is concidered an intermediate between lizards and snakes.

are there others that are still living.
if so please show sources, as i would love to further my knowledge of evolution.

Answer 1

It's interesting to look at apparently intermediate species that are around now and muse on what they tell us about evolution, but bear in mind that they are living now; they may or may not be closely related to the species that did form the actual intermediate, millions of years ago. To take your example of legless lizards: I think the earliest snake fossils date back to the beginning of the Cretaceous period and appear to be related to the monitor lizards. Legless lizards like the european slow worm are probably much more recent and belong to a different group, with members that still have legs. You are not looking at evolutionary intermediates here, but at parallel evolution - similar answers to similar questions.
Not that these analogous anatomies are irrelevant to evolution: what pressures might lead a species of lizard to do better without legs? Moving underground, moving through closely packed vegetation, moving through water. I think current opinion is that snakes probably evolved in an aquatic or semiaquatic environment. The current legless lizards may or may not have come that particular route.
Good luck with your exploration of evolutionary intermediates, but be careful how you interpret them.

regards
Graham

Answer 2

Depending on how you look at it, there are no intermediates, or everything is an intermediate.
Since evolution is a generally slow process, then all species that currently exist have adapted to their current form depending on the current environmental and other adaptive pressures. They are the final product for the current biological environment. So they are not intermediate.
Since evolution is an ongoing process, then all species are constantly adapting to adaptive pressure, so they are moving from one species into another, we will all become a different species of human given enough time. Any particular species, say, unless it becomes extinct, may split into different species if allowed to survive for long enough under different adaptive stresses. So we are all intermediates.

The legless lizard is not an intermediate between lizards and snakes, it just shares physical characteristics of both snakes and lizards.

Answer 3

There are only intermediates if you set a starting point and end point for evolution (for example, from "lizards" to "snakes"). For all we know, *we* might one day be considered an "intermediate" between primates and some higher life form. If you think about it, evolution is a continual and never-ending process, so everything is an intermediate between one species and another.

Answer 4

Lungfish are believed to be related to the fish that developed the ability to breathe air and survive on land.
http://en.wikipedia.org/wiki/Lungfish

Monotremes and marsupials are intermediates between mammal-like reptiles and modern placental mammals.
http://en.wikipedia.org/wiki/Monotreme
http://en.wikipedia.org/wiki/Marsupial

Answer 5

1. Coelocanth, a lobe-finned fish from Madagascar,
2. Montotremes - platypus and echidna are egg-laying mammals.

etc.etc.etc.