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Showing posts with label l3 Bio. Show all posts
Showing posts with label l3 Bio. Show all posts

Monday, 11 April 2022

Who (and what) are the Croods?

 In the 2013 film 'the Croods' we follow a caveman family who navigate a changing climate (and impending doom). Instead of analysing the actual movie, i'm gonna be a bio weirdo and decide which species the Croods are. so, let us begin....



So, we have a bipedal family (walk around on two legs) throughout the movie. Sandy (the very small child) walks quadrupedal, though this could be due to her being a toddler (a very murderous one at that). They have relatively small teeth and jaws, with a small fore head but also a small degree of prognathism. Using this facial structure, we can eliminate the Australopithecus genus.

Their clothing is reletively complex, being form fitting and made of different materials, likely using some form of sewing. Eep also wears a necklace, suggesting their are capable of more complex thought, potentially with the necklace having a symbolic meaning. They use very basic tools, but not fire, suggesting that they are part of the Oldowan tool structure. When it comes to their hunting tactics, they use communication but not a large amount of tools, also fitting in with the Oldowan tool culture. Their shelter is a natural cave, rather than a free standing hand made shelter, suggesting that they are from the early homo genus. They are shown to eat foods such as raw eggs and meat, which is high (but would be higher if they were cooked) in energy, compared to fibrous plants.

Using this information, I would predict that they are either late Homo Erectus or early Homo Heidelbergensis (hypothesised to be the predecessor to Homo Neanderthals). Both these species are primarily bipedal, have smaller foreheads and use early stone tool culture. How ever, with the Croods, there are a few weird features. They are shown to have complex thought such as grief when Grug is left behind and they mourn his death by blowing their shell horns. They also have very advanced clothing, which could possibly just be a design choice, but where is the fun in that? These features fit better with the Neanderthal genus, so they are a weird species. They also use art (shown by Grugs story telling) which makes this a little more complicated to get a definitive species.

In conclusion, I believe that the Croods family are members of the late Homo Erectus/ early Homo Heidelbergenis species, as shown by both their biological and cultural evolution demonstrated within the film.

In the initial narration, Eep suggested they are neanderthals, but I don't really care. Its a movie anyways.

Tuesday, 15 March 2022

Not just the power house of the cell.

Biology: Mitochondrial DNA


 In 1987, a group of scientists published a paper about mitochondrial DNA and the common mitochondrial ancestor that humans all over the world share. Mitochondrial DNA is different from nuclear dna and is only inherited maternally (from mothers, because sperm cells do not contain mitochondria). The DNA stays relatively unchanged throughout generations and the only source of variation is mutation (which occurs at a slow and steady rate). Human mitochondrial DNA codes for around 37 genes (compared to nuclear DNA which codes for around 30,000 genes). The mitochondrial DNA that the scientists tested was from all over the world and can all be traced back to a singular woman who lived (probably in Africa) around 170,000 years ago. This woman is nicknamed “mitochondrial Eve”. The average differences in the mitochondrial dna of the participants of the study was 9.5. The DNA difference within a group (eg. just in Europe) is higher than the difference between groups (eg. between Europe and Asia). It was also found that Africa had the highest number of mutations (probably because that is where the lineage started) and Australia had the lowest number of mutations (because humans immigrated there relatively recently). They claimed in their conclusion that a larger sample size would have given a more definitive answer about the lineage of mtDNA.

Friday, 11 March 2022

That awkward moment when your fossil gets found in a cave.

 In level three biology, we have been learning about human evolution. As a fun add on, we have learnt about a random species found in a cave system in south Africa. This species is an interesting thing, where it contains both human like features and ape like features. Another annoying challenge is the lack of surrounding rock and other substance, that makes working the age of this species a bit difficult. 

Homo Naledi

Australian museum (2019)

https://australian.museum/learn/science/human-evolution/homo-naledi/


Whilst on a cave expedition in 2013, two cavers found themselves in an unexplored part of the ‘rising star’ caving system (in south Africa). In this unexplored chamber, there were many human like fossils. This was a huge scientific discovery. The call went out for more cavers (who were small enough to fit through a narrow part of the cave. The 6 most qualified people who were chosen to collect the fossils were all young women. ‘Naledi’ comes from the word for ‘star’ in the local Sotho language. The strange thing about Homo Naledi is the combination of advanced human like features (shape of skull, hand structure, foot structure and the bottom half of the pelvis) along with earlier features (small stature, small cranial capacity, robust collar bones and arm bones which suggest climbing). The remains were also found in a cave, but there is no evidence that they were dragged down by predators. It is also very unlikely that the amount of homo naledi found in the caves just got lost and died. It is more likely that they were buried, in a ritualistic manner. This would suggest the potential of abstract thought and rituals within the species. Then again, its not like we can go back and ask them :)