Althouse: "It is not common to have a dual emergence between Broods XIII and XIX. They occur once every 221 years and the last time these two broods emerged together was in 1803."

January 11, 2024

"It is not common to have a dual emergence between Broods XIII and XIX. They occur once every 221 years and the last time these two broods emerged together was in 1803."

Metafilter links to "Cicada Safari/Mapping the double emergence of Broods XIII and XIX."

14 comments:

rehajm said...: A cacophony from cicadas and an election year. Now it's 'Ew'...; 1/11/24, 11:08 AM
Justabill said...: They should have a lot to catch up on.; 1/11/24, 11:23 AM
Mr. O. Possum said...: I hear there's a lot of buzz about this story.; 1/11/24, 11:39 AM
D Books said...: Makes sense: a 13 year cycle and a 17 year cycle sync up every 13x17=221 years. There’s a reason prey animals should have prime number lifecycles.; 1/11/24, 11:53 AM
Birdchaser said...: Iv been keeping track of cicadas since I was 10 & have collected them for 55yrs. Still have the first one I ever caught. I have traded our cicadas for other cicadas from all over the world.; 1/11/24, 11:55 AM
Big Mike said...: Back in the day a professor who was a member of the ACM Special Interest Group on Ada Programming Language had a lucite block on her desk — with a cicada embedded therein. Special Interest Group (SIG) on Ada — SIGAda. I appreciated the pun, though I hated the language.; 1/11/24, 1:14 PM
Narayanan said...: does that mean lotsa insects for futuristic food supply?; 1/11/24, 1:20 PM
Whiskeybum said...: From the article:

• Periodical cicadas are best eaten when they are still white, and they taste like cold canned asparagus. Like all insects, cicadas have a good balance of vitamins, are low in fat, and, especially the females, are high in protein.

I guess there’s no reason to stock up on cold canned asparagus this year.; 1/11/24, 1:38 PM
Owen said...: Are there genetic differences among the Broods? Presumably they "inbreed" with others of their same strain (when they emerge, they are the "only game in town," right?) and so there would genetic drift distinct to the brood, different in kind or degree to that seen in other broods.

How do you measure the "success" of a Brood? The average lifespan of its members? The number of eggs (and eventual offspring) its members produce? Does "success" vary across Broods: I would imagine yes, because the environment into which the Broods emerge will vary in hostility from year to year...; 1/11/24, 1:44 PM
Quaestor said...: Owen writes, "Are there genetic differences among the Broods?"

Obviously. And in those rare instances of dual emergence, there will be hybridization between the two cicada species, Magicicada septendecim (the 17-year cicada) and Magicicada septendecula (the 13-year cicada), not two strains of a single species. However, the occurrence of hybridization is quite limited by geography. The 17-year cicadas have a more northerly distribution. The incidence of crossbreeding will be confined to those very limited areas of overlapping ranges. Taxonomy is a product of the human intellect. Regrettably, Nature seems unimpressed by our efforts to make her obey species boundaries. Instances of fertile hybridization are remarkably common, even in the higher vertebrates, yet separate species manage to preserve their distinctiveness.

All of us learned to use a simple Punnett chart in middle school when we studied the work of Gregor Mendel. However, heredity is a bit more complex than that. We were taught that inbreeding was detrimental to the species, yet Nature relies on it in many cases. Inheritance isn't a fixed recipe for an organism, if one sequence is bad, there's often a useful duplicate somewhere else in the genome. Sex as a reproductive function is bound to go wrong from time to time, yet Life gets by somehow. Take for example radiation-induced mutation. Given cosmic rays, solar eruptions (it turns out our Sun is a naughty star), and the occasional commie reactor mismanagement, we should be up to our ears in Godzillas, but we're not. Corrupted genomes often have enough replication to repair themselves. The animals living in the Chornobyl Exclusion Zone often contain nasty amounts of strontium 90 in their bones, yet they look, behave, and reproduce like their non-radioactive cousins. The reason for this resilience seems to be the prevalence of segmental duplication, the nearly identical, repeated sections of DNA that comprise a surprisingly large portion of any known genome, including ours. We have 22,000 genes, many of them duplicates or near duplicates. 17-year and 13-year Cicadas have about 26,000 and 28,000 respectively. If humans are as biologically complex as sap-sucking bugs, then the cicadas can endure a bit of cross-species hankypanky.; 1/11/24, 6:22 PM
Josephbleau said...: Under modern racial theory, race does not exist(see Lewontin) yet race is the most important thing to worry about today.; 1/11/24, 10:20 PM
Oligonicella said...: Narayanan:
does that mean lotsa insects for futuristic food supply?

That would definitely be what you'd call a feast and famine scenario.; 1/11/24, 10:39 PM
Oligonicella said...: Quaestor:

To add to the sex related abilities of insects: there are a decent number of parthenogenetic insects (and not a scent number of higher forms). Our southern mantid, Brunneria borealis is one. Our only Brunneria species, it's a split from the rest of the genus in SA. Those look almost the same but are not parthenogenetic.

It's also pretty weird from the rest of our US mantids in looks, habits and egg case. Very languid and docile.; 1/11/24, 10:58 PM
mikee said...: Trivial fact: Corgis love to snack on freshly molted cicadas.
Do with this knowledge what you will.; 1/12/24, 9:44 AM