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Laura K Hayward

@lkhayward.bsky.social

108 followers 87 following 6 posts

Postdoc at IST Austria, population genetics

Posts Replies Media

Laura K Hayward @lkhayward.bsky.social · 24/08/2025

The absolute difference between them — sexual dimorphism (grey) — can stay nonzero for many generations, changing rapidly when rfm is lower (a, b) and more slowly when rfm is higher (c, d)

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Laura K Hayward @lkhayward.bsky.social · 24/08/2025

Not typically. Supplementary Fig. 6 shows example trajectories of female (red) and male (green) trait means over time at different intersex correlations (rfm). In panel c, for instance, with rfm = 0.95, the two means drift in a correlated fashion near the shared optimum (at 0)

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Laura K Hayward @lkhayward.bsky.social · 24/08/2025

Full paper now out in GENETICS: The relationship between sexual dimorphism and intersex correlation: do models support intuition? 🔗 academic.oup.com/genetics/art... #Evolution #QuantGenetics @GeneticsGSA

academic.oup.com

The relationship between sexual dimorphism and intersex correlation: do models support intuition?

Abstract. The evolution of sexual dimorphism (the difference in average trait values between females and males, SD), is often thought to be constrained by

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Laura K Hayward @lkhayward.bsky.social · 24/08/2025

A central focus of the paper is the classic expectation that sexual dimorphism and the intersex genetic correlation should be negatively related. This intuition is widespread in #QuantitativeGenetics — but our models show it’s not guaranteed. Sometimes the trend can even be positive.

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Laura K Hayward @lkhayward.bsky.social · 24/08/2025

Here’s Fig. 1d: for certain parameter choices, just by chance, the mean trait values in females and males can differ by about half to almost a full phenotypic standard deviation. 👉 Drift alone can create substantial dimorphism.

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Laura K Hayward @lkhayward.bsky.social · 24/08/2025

Why do males and females often differ in traits? The expected answer: selection. But our new paper in GENETICS shows that genetic drift alone can generate sexual dimorphism — even when male & female optima are the same

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