We are chordata!


After seeing this Youtube video by AronRa, I was inspired to make a related tweet. You know how it is.


[link]

As you can see, it's not a very popular tweet. Still, it's what this post is about; Human taxonomy.

We are classified, by scientists, according to the similarities and differences we share with other organisms. This classification is done with the help of different fields within biology: embryology, morphology, genetics, etc.

Ever since Linnaeus, thousands of biologists have been working on his taxonomic framework, expanding it and improving it. Thanks to the advent of DNA sequencing, phylogenetic trees are used to improve and refine it even further. No organism has ever been found on earth which doesn't have DNA. All organisms on earth have DNA sequences in common with each other.

The top most global classification of humans is Neomura. We belong to a group of organisms that have glycoproteins. This is our Superdomain. We are neomuran. We share this classification with Archaea, a type of bacteria. [There are bacteria that do not share this classification with us].

The second most global classification of humans is Eukaryota. We belong to a group of organisms that have membrane-bound organelles. This is our Domain. We are eukaryotes. We share this classification with plants.

The third most global classification of humans is Opisthokonta. We belong to a group of organisms that have a flagellum in our reproductive cells. We are opisthokonts. We share this classification with fungi.

The next classification is the Superkingdom Holozoa. This excludes fungi. We are Holozoa. We share this classification with sponges.

Another group classification is Filozoa. These have cells with threadlike projections. We are Filozoa. We share this classification with some amoebas.

We belong to the Kingdom Animalia. Animals can move freely. We are animals. We share this classification with jellyfish.

Subkingdom Eumetazoa. Animals in this group have cell tissue and neurons. We are Eumetazoa. We share this classification with sea anemones.

Superphylum Bilateria. As the name indicates, animals in this group have bilateral symmetry. Basically, we have similar left - right sides as well as not similar up - down and front - back. We are Bilateria. We share this classification with flatworms and insects.

The Deuterostomes have both a mouth and an anus. (Some Flatworms have only a mouth, others have a mouth and an anus, others still have multiple anuses... the more you know). We are Deuterostomes. We share this classification with sea cucumbers.

Phylum Chordata. Finally we arrive at the level of my tweet. Chordates have a hollow dorsal nerve cord. We are Chordates. We share this classification with lancelets, fish-like animals that hardly have a brain.



Shall we continue?

We are Vertebrata (backbones e.g. lampreys)
We are Gnathostomata (jawed vertebrates e.g. fish)
We are Sarcopterygii (enamel on teeth e.g. lobe-finned fish)
We are Rhipidistia (bones in the skull, details of the skeleton e.g. coelacanth)
We are Tetrapoda (four-limbed vertebrates e.g. frogs, snakes, birds, dinosaurs)
We are Synapsids (openings in skulls. All mammals are synapsids. e.g. platypus)
We are Mammalia (mammary glands e.g. rodents)
We are Theria (give birth to life young e.g. marsupials)
We are Eutheria (features of the feet, ankles, jaws and teeth. All placental mammals)
We are Boreoeutheria (placental mammals e.g. moles)
We are Euarchontoglires (based on DNA e.g. treeshrews)
We are Primatomorpha (binocular vision e.g. flying lemur)
We are Primates (relative large brains e.g. bushbabies)
We are Haplorhini (dry nosed primates e.g. tarsiers)
We are Simiiformes (Simians e.g. gibbon)
We are Catarrhini (nostrils that face downwards e.g. macaque)
We are Hominoidea (Apes e.g. orangutans)
We are Hominidae (Great Apes e.g. gorillas)
We are Homininae (Great Apes except orangutans)
We are Hominini (except gorillas)
We are Hominina (except chimps)
We are Homo (descendants of Australopithecus e.g. Homo Habilis)
We are Homo sapiens (modern human species e.g. Homo sapiens idaltu)

We are Homo sapiens sapiens, that's our subspecies.

Source: @karlmeyer

As you can see, our taxonomy and our shared DNA with these other lifeforms point to a shared ancestry of all life on earth.

I invite you to play with the timetree.org website to see the scientific studies associated with all this.

Edits - Added the Prentice Hall image at the suggestion of @KittenKoder and the image from @karlmeyer

Moved 'insects' to the correct level (Bilateria) at the correction of @kaimatai

I recommend reading this BBC article.

Comments

Post a Comment

Popular posts from this blog

Formal logic

Genesis 1:1 * describes the following logic Informally Premise P1: God exists. Premise P2: If P1 then "the universe is as old as the earth**". Conclusion C1: The universe is as old as the earth. Formally P1 → C1, P1        C1 This form of logic is called Modus Ponens. The truth of C1 doesn't imply the truth of P1 because there may be other explanations for C1. Lets look at the following classical example Premise P3: It rains Premise P4: If P3 then "the streets are wet". Conclusion C2: The streets are wet There are other possible explanations for wet streets: A cleaning crew just passed, there were games with water, the dikes were broken, etc ... However, we can say that, if the streets are not wet then it doesn't rain. Formally P3 → C2, ¬C2        ¬P3 This form of logic is called Modus Tollens and is the inverse of Modus Ponens. To return to Genesis 1:1. C1 is false and Modus Tollens applies. P1 → C1, ¬C1        ¬
Read more

Abortion

Image
You want your freedom - By Ashvin Harrison with permission In my opinion, the "abortion debate" isn't actually a debate. Some people want to give rights to fetuses that don't have cognitive abilities to exercise those rights while taking away the right of self-determination from women who do have cognitive abilities. Everything else is just smoke and mirrors. Is a fetus a human being? I really don't care if it is, or isn't. Does a fetus have the right to live? No, it doesn't. Human rights begin at birth according to the Universal Declaration of Human Rights. Let's imagine we give a fetus the right to live. How can we determine whether a fetus wants to exercise that right? We can't. That is not a right, but an obligation. These people want to force fetuses onto the world whether these fetuses want, or not. Let's imagine we take away women's right of self-determination, a right recognized in the Universal Declaration of Hu
Read more

Scientism

Image
" Scientism " means misusing the word " science ". You can misuse it either by calling something that can't be measured "scientific", or by claiming that something without sufficient supporting evidence is "scientific". It is a word that's thrown around by people who hardly know what it means and who certainly don't know what the word "science" means or what the scientific method is. "Scientism" is also a word used in philosophy to denote an excess of confidence in science, and has legitimate uses. However, the people who accuse others of "scientism" are not at all interested in philosophy. They are solely interested in delegitimizing the scientific method. They are anti-science . Period. Why are they against science? Is it because they are not scientifically literate? Do they have economic motivations? What worries me is the number of people that are anti-science. There's a war on science g
Read more