Why is josephus lyles so much slower than Noah?

Why was Michael’s brother Larry Jordan not in the NBA?

Why was Tariku Bekele not as fast as Kenenisa?

Why is Frank Stallone not as famous as Sylvester?

Why was slojo slower than wejo?

Same genes but not all the same genes are expressed in each sibling.

Used to watch them at every Virginia high school state meet. Knew I was witnessing greatness—getting to see the Lyles brothers sprint and Grant Holloway jump made me forget about my comparatively silly little races.

Josephus has essentially the same amount of talent as his brother, and that was evident if you watched them race in high school. They were always battling with each other for supremacy, with Noah winning more often but by razor-thin margins. Josephus was and still is an unbelievable athlete, and his pro PRs indicate that he’s been no slouch on the pro circuit (I think he’s run 19.9 in the 200 and 10.0x in the 100). But injuries have hampered his progression, and they are the main difference between him and Noah. Noah has been blessed with a relatively injury-free career so far, and Josephus has not.

Fwiw, I always thought Josephus would move up to the 400 on the pro circuit to carve his own path and because he has great speed endurance in addition to his rare top-end speed.

Siblings don't have the same genes unless they're identical twins.

I now think my wording of much slower was too harsh. Those times are super fast, just not in the same stratosphere as Noah. Injuries do make sense and can really change the trajectory of a runner.

Siblings share half of their genes. And it turns out that the genetic architecture of phenotypic differences across individuals is at least approximately linear for most traits (think, just adding up the effect of individual mutations, rather than interaction effects playing a large role). So, if Noah is +4 SD (a 1 in 10,000 talent), we'd expect Josephus to usually be about +2 SD (a 1 in 100 talent).

Siblings aren't as genetically similar as you think.

washingtonpost.com

Why siblings can be so different, according to science

Parents often marvel or complain about how different their kids are. But the real question is: Why wouldn't they be?

Link:www.washingtonpost.com/parenting/2023/...

(a few quick caveats - this type of math only works when one sibling is an extreme outlier, as is obviously the case here. Otherwise noise will swamp these effects. And even in the extreme outlier case, it's not like the other sibling will always be exactly half as talented, it is still noisy. And finally, this only applies to polygenic traits, i.e. traits controlled by a large number of loci. But that seems to be the case for most interesting traits, and I'd certainly expect sprinting talent to be highly polygenic. So anyway, all this really shows is that, as a baseline, it shouldn't be shocking if when one brother is super talented, the other brother is talented but doesn't quite match. That's exactly what we'd expect to usually be the case.)

Sub 20 in the 200m. Faster than the national records of all but maybe 4 countries.

Right-- brojos, Markezich sisters

Why is rojo so much smarter than wejo?

Why is Giannis Antetokounmpo so much better than Thanasis and Kostas?

Why is Brook Lopez so much better than his twin brother, Robin?

Why is Steph Curry so much better than Seth?

A that end of the physiologic extreme, its splitting hairs (and tenths). They are remarkably alike imo, among the best .000001% of all humans at running fast.

That’s why you should choose names for your children carefully. Noah sounds lean and mean. Josephus sounds like a stocky Roman foot soldier like Josephus Maxipygeus or something.

...if you believe some stories, these two might have different fathers.

There are some differences in physique(Josephus is taller) and like others have mentioned, some injury issues(got injured running the 200 his senior year, injured in 2023). I actually thought in HS that Josephus might've been on the same trajectory of Noah given that he is technically a year younger so he was hitting some of the times that Noah hit the year before and he beat him a few times in the 55m indoors despite training to be a 400 guy.