Scientists observe rise of a new species of Glapagos finch (1 Viewer)

[Ruff]

In case anyone misses this in their regular news feeds:

http://www.bbc.com/news/science-env...social&ns_campaign=bbcnews&ns_source=facebook

The Galapagos are a scientific gift that just keeps on giving.

 

[Andy Adcock]

Surely such a small gene pool won't persist?

How can a new species derive from the genetic input of just one male?

Someone will tell me I'm sure but this in humans, would lead to physical and mental abnormalities, they're all breeding with brothers and sisters.

The only comparable species would be Italian Sparrow but that's the result of a long term hybrid zone, not one lone lothario.


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[Mysticete]

I can't speak to the validity of the species (I think Darwin's Finches are oversplit as is), but deformities as a result of inbreeding don't always happen. It really depends on the genetic health of the founders. Inbreeding tends to result in recessive, harmful traits being expressed more often in a population, but if those traits are not present or not problematic in a given environment, they may not show up.

 

[Andy Adcock]

I can't speak to the validity of the species (I think Darwin's Finches are oversplit as is), but deformities as a result of inbreeding don't always happen. It really depends on the genetic health of the founders. Inbreeding tends to result in recessive, harmful traits being expressed more often in a population, but if those traits are not present or not problematic in a given environment, they may not show up.

Surely. such a limited gene pool will eventually present it's own problems, inherited or not?


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[Dave B Smith]

For background info on the finches on Daphne Major and the ongoing studies read the book 'The Beak of the Finch: A Story of Evolution in Our Time'. Really interesting book.

Note, this book was written prior to the "Big Birds" arrival on the scene so doesn't address this.

 

[Mysticete]

Surely. such a limited gene pool will eventually present it's own problems, inherited or not?


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Think about it this way...pretty much every island population, at least populations on islands far from the mainland, are probably descended from a very small number of colonists that were accidentally blown to the island during freak events.

 

[dantheman]

Also there are a number of species which have been brought back from the brink of extinction by breeding of a very small number of initially very closely related individuals.

(Of course scientists can partially select the most distantly related individuals from a small group to minimise potential inbreeding defects in some cases, but still ... )

 

[aeshna5]

Laysan Duck was certainly brought back from the brink from just a handful of remaining individuals.

 

[Andy Adcock]

Laysan Duck was certainly brought back from the brink from just a handful of remaining individuals.

A handful yes but we're talking about this population deriving from a single male?

Apparently, the endemic females would not breed with the new male due to vocal differences but have females of the newcomers bred with endemic males?

I find it hard to accept that this has come over just a couple of generations and from just one male

In relation to most animals, science has a minimum number of individuals required for survival of the species. This I believe is down to genetics and below that number, the species will be lost, anyone know that figure?



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[McMadd]

A handful yes but we're talking about this population deriving from a single male?
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Chatham Black Robin: all from 1 female "Old Blue". There's a plaque dedicated tot her for "saving her species" at the airport if you visit..

 

[Andy Adcock]

Chatham Black Robin: all from 1 female "Old Blue". There's a plaque dedicated tot her for "saving her species" at the airport if you visit..

But there was more than 1 male of her species I presume, we are talking about one male from another species, I just can't see that this can lead to speciation?

I am no scientist though.


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[Kratter]

But there was more than 1 male of her species I presume, we are talking about one male from another species, I just can't see that this can lead to speciation?

I am no scientist though.


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As Mysticete explained above, negative inbreeding effects are not always expressed, even when entire populations may be descended from a pair of individuals. Negative genetic effects may be ameliorated if the population rebounds quickly. As mentioned above, many oceanic island species were likely established by as few as a pair of founders.

Andy

 

[Andy Adcock]

As Mysticete explained above, negative inbreeding effects are not always expressed, even when entire populations may be descended from a pair of individuals. Negative genetic effects may be ameliorated if the population rebounds quickly. As mentioned above, many oceanic island species were likely established by as few as a pair of founders.

Andy

As I said before Andy, the only current comparison would be with Italian Sparrow which has a broader, almost permanent contact zone in which it hybridised.


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