One of the most extraordinary things about the shock of an asteroid that hit Earth 66 million years ago is not what died , but what survived . A fresh bailiwick receive that one club of marine algae made it through by change its source of energy , feeding on other life mannikin instead of harvest home sunlight . In the procedure , they greatly speed up the recovery of oceanic ecosystem .
In the Cretaceous , as today , photosynthetic algae formed the base of the loose sea ’s food webs . When the asteroid expunge , causing the Cretaceous - Paleogene Extinction Event , or K / PG , the world became shrouded indarkness from sootcutting off access to sunlight .
" If you transfer algae , which form the base of the solid food chain of mountains , everything else should die . We wanted to know how Earth ’s oceans avoided that luck , and how our modernistic marine ecosystem re - evolved after such a cataclysm . " Professor Andrew Ridgwell of the University of California , Riverside said in astatement .
Coccolithophoresare photosynthesizing single - celled algae with Ca carbonate scales . Studying those entomb on the seafloor at the beginning of the Paleogene geological era , Ridgwell retrieve the fossilize shell have hatchway that indicate they once had scourge to move around , although these have not been preserve . advanced coccolithophores with scourge squander bacterium and smaller algae , in summation to the vim they capture from sunlight , using the flagellum to move in on their prey .
Moreover , Ridgwell and carbon monoxide gas - authors cover inScience Advances , long after the asteroid struck , many of the rife coccolithophores were those that during the Cretaceous had been restricted to continental shelves . Today species living on these shelves are much more likely to supplement their Energy Department intake by feed on other life than their receptive ocean counterparts .
The authors draw the end that during the Cretaceous , coccolithophores were much like today – most relying on sun alone , but some , in particular on continental shelves , snacking on even tinier creatures as supplement . In a menstruum of global darkness those with only one source of vigour die , but the so - called “ mixotrophic species ” survived , reuse nutrient from the before - times .
Once sunlight hark back , mixotrophic coinage remained rife for 1.5 - 2 million class until exclusively photosynthesizing species evolved again to reclaim the unfastened oceans .
The writer were pose as to why the mixotrophic coccolithophores remained prevalent for so long . They create a computer model providing a simplified version of weather condition after sunlight return , and found it intimately replicated what they had understand , with mixotrophy remaining widespread for long time period of time once established .
" Mixotrophy was both the means of initial natural selection and then an advantage after the post - asteroid darkness lifted because of the abundant small pretty electric cell , likely survivor cyanobacteria , " Ridgwell said . " It is the ultimate Halloween story – when the luminousness go out , everyone starts corrode each other . "
The findings fortify the case it was the extended dark , rather than drastic temperature change or ocean acidification , that most affected the basis of the marine food web situation - impingement .
