Eggs and live birth

[Sriram]

Hi everyone,

A case of evolution in transition. A lizard lays eggs and also has a  live birth in a single pregnancy.

https://edition.cnn.com/2020/04/11/us/skink-species-evolution-transition-scn-trnd/index.html

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For most of the animal kingdom, babies are born in one of two ways: their parent either lays eggs or gives birth to live offspring.

Recently, a three-toed skink (Saiphos equalis) pulled off an extraordinary feat: It laid three eggs and delivered another baby through live birth in the same pregnancy. That suggests that the lizard species is in a rare transitional form between egg-laying and live-bearing animals, according to a study published in Molecular Ecology last month.

Three-toed skinks, found in Australia, are already a fascinating species for evolutionary scientists, explains Whittington. One reason is that some populations reproduce by laying eggs, while others reproduce through live birth.

The mode skinks use to reproduce generally corresponds with their environment. Skinks around the Sydney area lay eggs, albeit ones with thin shells and embryos that are almost completely developed. In northern parts of Australia, the skinks give birth to live young.

But never before had scientists seen a species lay eggs and experience live birth in a single pregnancy until it was observed in the three-toed skink last year, Whittington wrote. It was the first record of a vertebrate doing so.

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Cheers.

Sriram

[Sassy]

Hi everyone,

A case of evolution in transition. A lizard lays eggs and also has a  live birth in a single pregnancy.

https://edition.cnn.com/2020/04/11/us/skink-species-evolution-transition-scn-trnd/index.html

***********

For most of the animal kingdom, babies are born in one of two ways: their parent either lays eggs or gives birth to live offspring.

Recently, a three-toed skink (Saiphos equalis) pulled off an extraordinary feat: It laid three eggs and delivered another baby through live birth in the same pregnancy. That suggests that the lizard species is in a rare transitional form between egg-laying and live-bearing animals, according to a study published in Molecular Ecology last month.

Three-toed skinks, found in Australia, are already a fascinating species for evolutionary scientists, explains Whittington. One reason is that some populations reproduce by laying eggs, while others reproduce through live birth.

The mode skinks use to reproduce generally corresponds with their environment. Skinks around the Sydney area lay eggs, albeit ones with thin shells and embryos that are almost completely developed. In northern parts of Australia, the skinks give birth to live young.

But never before had scientists seen a species lay eggs and experience live birth in a single pregnancy until it was observed in the three-toed skink last year, Whittington wrote. It was the first record of a vertebrate doing so.

***********

Cheers.

Sriram

Can you post the video recording the live bird. Do you think other factors involved?

[Harrowby Hall]

Sassy, skinks are lizards not birds.

[Sriram]

Can you post the video recording the live bird. Do you think other factors involved?

Sassy,

This is not about a bird....its about a lizard both laying eggs and also giving live birth to an offspring in the same pregnancy.

If you mean a video of the live birth....there is no video that I know of.  I have attached the link in the OP.

[ippy]

I expect it'll be more of the same whichever one the egg layer or the live birth ends up being the one that has best survival rate, it sounds like this creature is likely to be one of those mutations that by chance happens to be in the process of one of those changing moments, very interesting!

Regards Sriram, ippy.

[Steve H]

I suspect that Sassy meant to type "live birth", but made a malpropism, perhaps because the mention of eggs caused an unconscious association.

[Robbie]

Good morning Sassy (from a distance), long time no see.  Also namaste to sririam.

I agree it's probably a mutation, may happen more than we know in the wild. Interesting nonetheless.

[Sriram]

Good morning Sassy (from a distance), long time no see.  Also namaste to sririam.

I agree it's probably a mutation, may happen more than we know in the wile. Interesting nonetheless.

Namaste Robbie!       You may have to keep up the namaste for several months or years in the future....  No more shaking hands...!

[Robbie]

I like namaste, it's elegant. If I live to go out of the house to work again I'll wear a hooded wetsuit, goggles and mask. I'll buy two so can wash one out each day when I get home, they dry qquickly  . I could be hosed down in the garden in good weather.

 For social occasions something like this with adaptations around the face to facilitate eating:-
https://www.funidelia.co.uk/adults-spiderman-marvel-deluxe-costume-34037.html?gclid=EAIaIQobChMI1J3eyI7s6AIVFeDtCh3pugsAEAQYAiABEgIzp_D_BwE

Reading that some skinks lay eggs with very thin shells through which the babies can be seen and others give birth to babies with protective shells, seems probable that particular lizard's last egg was about to pop anyway and merely shed its shell during labour. The skinks are a fascinating work in progress.

[Harrowby Hall]

If I gather some skinks in, say, the north of Queensland and transport them to the outskirts of Sydney, would their method of delivering their young change?

[Udayana]

If I gather some skinks in, say, the north of Queensland and transport them to the outskirts of Sydney, would their method of delivering their young change?

https://www.theguardian.com/environment/2019/apr/03/very-very-unusual-australian-skink-lays-eggs-then-gives-birth-to-live-baby

"Previous research has shown that if a Sydney skink was taken north it would still lay eggs, while live bearers transferred south would also continue to reproduce as they previously did"

[Harrowby Hall]

Thank you.

[Walter]

Thank you.

when I was in North Queensland I was delighted to make the acquaintance of  a few skanks , made the evening quite exciting .