Discussion was started with a question by @Smiti
"How Darwin finches changes its peak from V to U when they are getting nut as a food "
How exactly change in Phenotype cause change in genotype
As per the discussion;
There is a Normal finch with V shaped beak will produce 3 baby finches with same beak as parents .
whenever the V shaped finches reaches to a island( Nut as a food) it changes to V shape to U shape !?
What exactly happening !
As per explanation ;
V shaped finches changes its beak into U ,when they are getting nut as a food .
According @Seema CUBE this will repeat .
ie U shaped finch produce V shaped progeny ,this V shaped beak finches produce V shaped finches .this will continew
But some point of view that may correct !!!
But there is something happening with in a period of time then U shaped finch will resulting into U shaped progeny only .
But How !??!??
We heard with Lamarck theory about Inheritance of acquired character 
like short necked giraffe changes to long neck
giraffe:giraffe:
@Seema CUBE said this theory was not accepted .
According to germplasm theory:mouse2:
this lamarck theory of acquired character got rejected .
So now the question is " How this change is happening" !?
How the change phenotype influence the change in Genotype!!???
Seen here is adapted radiation of finch A. (Geospiza magnirostris) into three other species of finches found on the Galapagos Islands. Due to the absence of other species of birds, the finches adapted to new niches. The finches’ beaks and bodies changed allowing them to eat certain types of foods such as nuts, fruits, and insects.
Chatshaala 6/12/22
Possible model system that can be linked to the evolution for ISEB conference were discussed
One of which is whitefly and Phyllantus model system
White fly Bemsia tabaci acquired gene coding for malonyltransferase from plant via HGT ( horizontal gene transfer) to protect itself from toxic phenolic glucoside (secondary metabolite produced in plants)
Why only whitefly can do this ? How does it actually occur ? Why is it evident now in today’s scenario? How can we connect whitefly to evolution?
To answer the questions we need to understand why these changes occur?
One possible reason is due to mutation
Eg: Sickle cell anaemia
It is point mutation in protein of hemoglobin in which one amino acid G A G ( glutamic acid) gets substituted with (valine) G T G as a result of mutation in one of the nucleotide base
Hemoglobin is made of heme(Fe) to which oxygen is bound to and
globin (protein= alpha and beta)
Glutamic acid is acidic amino acid and is charged hence due to repulsion it separates and gives hemoglobin in RBC it’s characteristics shape (normal)
mutation occuring results in valine which is neutral and hydrophobic amino acid due to which hemoglobin stick close to each other resulting in formation of sickle shaped RBC
Due to this less oxygen gets transported in body
However Sickle cell anaemia in tropical regions is beneficial as it makes individual less prone to malaria
One of the stages of plasmodium protozoa causing malaria called merozoite stage occurs in RBC where infection is detected…if RBC is sickle shape these protozoa can’t enter RBC thereby no malarial infection
What is the difference in Sickle cell trait vs Sickle cell anaemia ?
Then we talked about @_Seema_11 hypothesis as she told that when finches travel from the island of grain to island of nuts, their beak shape chaged from v shape (small & pointed) to u shape (strong and big)
This will happen with only those finches who successfully learn to survive by eating nuts When they start reproducing, their progeny will have v shaped beak but eventually as they start eating nuts, their beak shape will also change This will go on for years until their gene that is coding to give a shape to their beak also changes from v shape to u shape and as it is due to EVOLUTION this process will take long time
Coming back to Darwin’s finches …how do they change beak shape ?
In finches feeding on cactus fruit had long beaks than ground finches,
Here Calmodulin was expressed are high level.
Calmodulin is a signalling protein and it is seen to regulate the gene expression in finches feeding on cactus fruit
Calmodulin gets activated and increase in number when Ca2+ is in high concentration
Cactus fruit has high amount of calcium as a result of which high amount of calmodulin is produced in finches leading to change in beak shape
This can be compared to activity of lac operon which is regulated by glucose and lactose
Wherein at high lactose concentration the lac operon expresses itself
Hence change is beak shape is epigenetic phenomenon and not due to mutation
Epigenetic phenomenon is due to behavioural and environment change :
Incase of Darwin’s finches it can be said to be behaviour as feeding habits change
Incase of sickle cell anaemia , it is due to environment ie malarial infection is prevented in people living in tropical regions by mutation resulting in Sickle RBC
(Summary on 6/12/2022 by @Ichha )
To protect from malaria ,natural selection act as way in which increasing the sickel cell trait in a population .There by protect people from malaria .
But Still how the natural selection occured !?
the sickle-cell variant (i.e., the HbS allele) has been identified in four distinct genetic backgrounds in different African populations, suggesting that the same mutation arose independently several times through convergent evolution.
So this could be spontaneous mutation !!!
If sickel cell anemia is prominent due to mutation then how the Darwin finches got different path of evolution !?Like Ca- calmodulin concentration depending gene regulation !!!
Today we had an interesting discussion started with Darwin finches…
We discussed that Darwin observed birds with the different beak shape on the same Island. ( Galopogas)
The major question that got cleared today was,
Why the beak shape changed!!?
To address this question let us consider that there’s population wherein there were majority of birds with short beak which fed mainly on grain… 
In that birds population due to variation there are some birds with long beaks…
So say if we take an example with 10 birds then among them 8 have short beak & remaining 2 has long beak…
Now, the natural selection comes into picture…, Wherein due to fungal infection the grain producing plants die and flower 
producing plants remain on the island…
So due to this those 2 out of 8 will survive , grow, and reproduce and give rise to more number of long beak shaped birds & others which were short beak will move to another island or get extinct in that island…
HOW SICKLE CELL ANEMIA CAN BE RELATED TO DARWIN FINCHES?
We discussed that change in the shape of the beak arises due to mutations…
To understand mutation we took an example of a DNA sequence in which there is a mutation ( a kind of mistake) in certain nitrogenous base that results from normal short beak to long beak…
In case of sickle cell anemia GAG changed to GTG which further changes the sequence in RNA , and later after translation the protein produced in normal cell is glutamic acid while in sickle cell anemia is is valine…
Just because of this small change in chromosal dna sequence the normal rbc’s 
biconcave shape changed to sickle shaped…!!
What’s the difference between Glumatic acid and Valine that results in changes in shape of RBC!!
(7/12/2022 summary by @_Seema_11 )
Nothing in biology makes sense expect in the light of evolution 
How evolution is related to icchas work on Whitefly !!!
@Ichha from RJ college is working on Phyllanthus .
So what is a Phyllanthus !!
Phyllanthus is a plant which is close related to gooseberry plant .
Both are under the same family !?
Yes but Gooseberry:shamrock: plant is a tree while Phyllanthus that cubists are working on is a small herb .j
@Shraddha describes about the "Sleep- wake cycle in Phyllanthus* .Like human beings, we sleep at night wake up at morning .
Is this circardian rhythm seen ( visible 
) in all plants plants !!!
Not all plants ,but Phyllanthus ,Tamarind ,touch me not etc. showing this rhythm associated with their leaves. 
Like leaves opening at day and closing at night .
I want to fly ,so i should develop wings Vs i have wings so i can fly:eagle:
Issues of understanding in Evolution :
@adithya joshi explains about the confusing terms in evolution .
Which include Mutation,Natural selection and evolution.
@Aditya Joshi @Khushi made a interesting discussion starting with a quote ""I want to fly ,so i should develop wings Vs i have wings so i can fly ""
if mutation is a cause of change in a the neck length in girafee:giraffe: is this because of the girafee:giraffe: want to change its short neck to long neck then they are changing(Deliberate mutation )
or it happens by chance ( Chance mutation ,)!!!
But had a comment that " Do we have a proof of short neck jirafee ,so why not only long neck girafee were exist !!!
Later both are came at a single point where all these organisms may arise from a single
common ancestral .
Mistakes ,mistakes ,mistakes i dont like mistakes ,i avoid it …But mistakes likes me …so i can’t avoid .
I tried to explain @Ichha ichha’s finding on phyllanthus and Whitefly
Let’s take a look;
Plant produce secondary metabolites to fight against pathogens .
Phenolic glucoside is the one that ,when caterpillar comes and eating its leaves, plant can produce Phenolic glucoside& fight against them .
What will happens ,if Suppose caterpillar acquiring a detoxifying gene from a plant ,That can detoxify the Phenolic glucoside produced by plant !!
How this mechanism can possible!!!
How can plant gene will acquired by caterpillar !!!
Can we think of horizontal gene transfer !? 
will this gene transfer occured with the help of virus or bacteria !?
Do transformation have any role !!
if Suppose;
Virus attacking to plant & viral multiplication:microbe: take place later the plant detoxifying gene will incorporated to viral genome .when virus attacking to caterpillar “do that gene transferred to caterpillar” !!!
First known horizontal gene transfer between in plant and a Whitefly:shamrock:
Instead of caterpillar:bug: can we think of Whitefly:fly: ;
Plant Producing a Phenolic glucosides which is toxic to Whitefly .
By Horizontal gene transfer Whitefly acquired BtPMaT1 gene
.BtPMaT1 Catalyse the malonylation by malonyltransferase( adding a malonyl group to enzyme )of phenolic glycosides result in
phenolic malonylglucoside which detoxify the effect of phenolic glucosides .
This was thing i tried to explain,but i forgot to mention about Phenolic glucoside.
Haldane hypothesized that these disorders had become common in these regions because natural selection had acted to increase the prevalence of traits that protect individuals from malaria. Just a few years later, Haldane’s so-called “malaria hypothesis” was confirmed by researcher A. C. Allison, who demonstrated that the geographical distribution of the sickle-cell mutation in the beta hemoglobin gene (HBB) was limited to Africa and correlated with malaria endemicity. Allison further noted that individuals who carried the sickle-cell trait were resistant to malaria (Allison, 1954).
https://www.nature.com/scitable/topicpage/natural-selection-uncovering-mechanisms-of-evolutionary-adaptation-34539/
@_Seema_11 @Ichha @khushi @Arunan @KiranyadavR @Himanshu