The living Dinosuar of our time roams around us in a swamps, in bacteria-stagnant swamp waters, from tuffen boney plates, built in GPS, to up to 3,000 spare teeth.

they have been documented to finding there way back home, when relocated 30 miles away.
have boney plates called osteoderms, that not only act as armor, the also work as solar panels to heat them up.
an epic immune system that even with the most gruesome injurys, their blood prevents any infection from accruing.
have thousands on spare teeth ready to be replace to those that break or fall out

Origin of life Theories

RNA world hypothesis

Miller Urey experiment

primordial soup

Fossil evidence ~about 7-8 MYA

Kingdom: Animalia

Phylum: Chordata

Class: Reptilia

Order: Crocodylia

Family: Alligatoridae

Genus: Alligator

Species: mississipiensis

Evolutionary History of the Alligator

Mesozoic Era

Triassic ~245-201 MYA

The Archosaur split the Pseudosuchia (crocodile linage) divided from the Avemmetatarsalia (dinosuar/bird lineage).
Early ancestors were agile and often bipedal.

Jurassic ~201-145 MYA

crocodylomorphs evolve: ancestors become and adapt to be more semiaquatic, sprawing lifestyle, filling ecological niches living alongside massive dinosuars

Cretaceous ~145-66 MYA

Rise of Alligatoroidea: a subfamily including alligators splits from true crocodiles and gharials. Early ancestoral alligator like the Deinosuchus reached sizes up to 35 feet.

Cenozoic

Paleogene/Neogene ~22-2.6 MYA

A greater survivor, the alligators survive the K-PG extinction event. The genus Alligator emerges in Eurasia and North America.

Quaternary/Pleistocene ~2.6 MYA-Present

Alligator mississippiensis the modern alliagators came and stayed.

The American Alligator Ecosystem (crown Archosuar)

Alligator Gut Microbiome

aiding highly acidic digestion
- fusobacteria, bacteroidetes, firmicutes

Nest Thermal Engineering

metabolic heat generates stables temperature
- influnences sex determination

Wetland (Anoxic Mud)

primitive prokaryotic niches
Asgard Archaea Habitat similiraties

Host-Microbe Coevolution

Robust innate immunity
unbroken linage to mesozoic

The Multicellular Greenprint of the Alligator

Celluar Adhesion:

Ancient evolutionary solution: developed a flexible extracellular matrix that is held together by structural proteins like collagen and cadherins (sticky molecules)
How it showed up in the Alligator: Dermal Armor & Bone Matrix, bulit on a collagen organized skeleton, from its flexible skin to its rigid osteoderms (makeup boney plates).
Survival Advantage: Cellular Adhesion allows the alligator to withstand extreme physical stress, and twist violently during a "death roll," and survie high impact fights without tearing apart.

Coordination & Signaling

Ancient Evolutionary Solution: Evolution of gap junctions which are microscopic pores between cells and electrochemical signaling pathways.
How it showed up in the Alligator: Synchronized Muscle Contraction through millions of individual muscles cells in the jaw that receive chemical and electrical signals simultaneously to clamp down at once
Survival Advantage: Alligators turn a collection of independet cells into a singular weapon produces a crushing bite force of 2,000 psi

Division of labor

Ancient evolutionary solution: Cellular differentiation where grouos of cells forfeit reproduction to perform specific physiological tasks.
How it showed up in the Alligator: Innate Immune Powerhouse that are specialized white blood cells, marcophages, constanly secrete antimicrobial peptides (CAMPs) into bloodstream.
Survival Advantage: Allows alligator to heal from massive amputations and territorial wounds in bacteria infested, stagnant swamp water without developing sepsis a fatal infections.

Bulk Transport

Ancient evolutionary Solution: Evolution of vascular system to pump oxygen and nutrients to cell buried too deep for simple diffusion.
How it showed up in the Alligator: A sophisticated four-chambered Heart, showing a specialized cardiovascular layout featuring featuring a controllable shunt the Foramen of Panizza.
Survival Advantage: Allows the alligator to alter its blood flow when diving, by passing its lungs to redirect oxygen exclusively to its brain and vital organs for deep underwater ambuses.

Key Alligator Viruses

Alligator Poxvirus: Double-stranded DNA virus

Regressive hypothesis: shows massive, gene heavy viruses still retain complex traits reminiscent of ancient parasitic cells

Endogenous Retroviruses: within their geneic code

Progressive hypothesis: trapped in the alligator geneome shows how viral genes and host gene swapped places over deep time.

West Nile Virus: deadly virus that hits Alligators farms hard

Virus-First hypothesis: the alligators super-immune system is a product of 80 Million years of both alligators and virus evolving side-by-side.

genetics and evolutionary processes

have to fix

macroevolutionary stability combined with robust micro-evolutonary variation
sex deterimined by temperature
- the thermal switch
- estrogen cascade
- inverted genetic hierarchy
high intraspecific heterozygosity
slowest rates of molecular evolution

phenotypic and metabolic pasticity

is a keystone species
the nest protector mutualism

Human Co-Evolution and Mutualism

The relationship of human and American Alligator has transition from turmoil to a form of symbiosis.

to hunting for food and clothing in native american tribes
to being saved by being placed in the endangered species act in 1967
to regulating the sex the alligators come up with in temperature by ranchers

References

Brochu, C. A. (2003). Phylogenetic approaches toward crocodylian history. Annual Review of Earth and Planetary Sciences, 31(1), 357–397.

Jones, C. G., Lawton, J. H., & Shachak, M. (1994). Organisms as ecosystem engineers. Oikos, 69(3), 373–386.

Merchant, M. E., Leger, N., Earls, E., et al. (2006). Antibacterial activity of serum from the American alligator (Alligator mississippiensis). Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 144(4), 451–456.

Nell, L. A., Frederick, P. C., Mazzotti, F. J., Vliet, K. A., & Brandt, L. A. (2016). Presence of breeding birds improves body condition for a crocodilian nest protector. PLOS ONE, 11(3), e0149572.

Rice, E. S., Kohno, S., John, J. S., Pham, S., Howard, J., Lareau, L. F., O'Connell, B. L., Hickey, G., Armstrong, J., Deran, A., Fiddes, I., Platt, R. N., Gresham, C., McCarthy, F., Kern, C., Haan, D., Phan, T., Schmidt, C., Sanford, J. R., Ray, D. A., Paten, B., Guillette, L. J., & Green, R. E. (2017). Improved genome assembly of American alligator genome reveals conserved architecture of estrogen signaling. Genome Research, 27(5), 686–696.

Rodda, G. H. (1984). The homing behavior of juvenile American alligators. Copeia, 1984(2), 438–445.

Ryberg, W. A., Fitzgerald, L. A., Honeycutt, R. L., & Cathey, J. C. (2002). Genetic relationships of American alligator populations distributed across different ecological and geographic scales. Journal of Experimental Zoology, 294(4), 325–333.

Ryberg, W. A., & Lawing, A. M. (2018). Genetic consequences and management implications of climate change for the American alligator (Alligator mississippiensis). In Alligators and Climate Change (pp. 123–138). Texas A&M NRI.

Seidel, M. R. (1979). The osteoderms of the American alligator and their functional significance. Journal of Morphology, 161(3), 251–285.

Western, P. S., Harry, J. L., Graves, J. A. M., & Sinclair, A. H. (1999). Temperature-dependent sex determination in the American alligator: AMH precedes SOX9 expression. Developmental Dynamics, 216(4-5), 411–419. <411::AID-DVDY12>3.0.CO;2-3

Wu, P., Wu, X., Jiang, T. X., et al. (2013). Specialized stem cell niche enables repetitive renewal of alligator teeth. Proceedings of the National Academy of Sciences, 110(22), E2009–E2018.

Yatsu, R., Miyagawa, S., Kohno, S., Saito, S., Lowers, R. H., Ogino, Y., Fukuta, N., Katsu, Y., Ohta, Y., Tominaga, M., Guillette Jr, L. J., & Iguchi, T. (2015). TRPV4 associates environmental temperature and sex determination in the American alligator. Scientific Reports, 5, Article 18581.