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52 thoughts on “Phylogenetic trees | Evolution | Khan Academy

  1. This is very clear and helped me understand the phylogentic tree for my exam. Also, your voice is crisp and smooth. So that helped too.

  2. Sir, could we also have the Cladogram as;
    1. The Lamprey branches off first because is does not share any characteristic with the rest of the organisms
    2. The Sea Bass is second because it has jaws as the others but lacks lungs
    3. The Antelope is third because it has lungs but lacks a Gizzard. However, it develops fur along the line
    4. The Bald eagle fourth because it has a Gizzard but developed feathers along the way
    5. Then, fifth will be the Alligator which remains on the main line of descent with the Gizzard

    I will appreciate your feedback

    Thank You

  3. Can someone explain this proves evolution? Couldn't you just say there was a common designer who used similar blueprints? (not trying to refute evolution… just dont understand it)

  4. Oh my word thank you so much. This was clear and very understandable. I hope I can get it right for my assignments and exams cause the organisms I’m getting are difficult.

  5. The instructor moved at a sufficient enough pace to avoid distraction. This person also spoke in basic terms which enhanced absorption of the material. Very well done! Thank you!

  6. Even if you don't believe in evolution you unfortunately have to know this sort of stuff for exams 🙁

  7. How would it change if we included a species with feathers but no gizzard? Would feathers become a separate branch independent of the gizzard branch? If so, how does one account for the fact that the bald eagle has a gizzard?

  8. Question for this cladogram – doesn't everything to the right of the organism you are comparing have the same recent ancestor and have the same number of similar traits. Wouldn't this make each of those things equally related- for instance the sea bass and the eagle or the sea bass and the antelope. Both have the same most recent ancestor and have the same number of shared traits?

  9. Just so you know, molecular evidence (genomic testing) works great with humans and closely related taxa, but fails completely in deep time studies with Mesozoic fossils.

  10. It's like this guy is my classmate.He explains every problem directly as if he was in my class Be it chemistry, Maths or Bio

  11. This confuses me. Do we not have tons or at least some fossil and genetic evidence to accurately place things where they belong? You keep stressing the hypothesis part but does not the fact we are so genetically identical to chimps help place us in phylo trees? You can do it strictly based on the traits but is the real phylo tree with accurate representations not actually being compiled slowly but surely scientists? We share Dna with all life on this planet, going back from bacteria to archaea and do on. Can we not now partly place many large divergences accurately? It may take mapping the genetic code of every species which is ridiculous there is quite possibly too much biodiversity, but do we not have some evidence? Is there no accuracy to what we are mapping? Humans share dna with bananas but much more dna with all mammals for example. Like how sibling are more closely related than cousins genetically. In reality and not hypothetical examples such as this do we not have some credence behind when scientists produce phylo trees.

  12. thank you!! I have a biology test and was away when my teacher taught this; this helped me understand it, so hopefully, I'll get a good grade!

  13. "Looks like" is not evidence. You can't get written instruction that is not there. You can only change what is already there.

  14. This is a platform where I learned Biology for my first year. Khan Academy is the best , main thing is its totally free.

  15. I love Khan Academy because it always tells me what I need to know in detail without any unneeded details! I am always able to learn exactly what I need to thanks to them. Thank you, Khan Academy. 🙂

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