diff --git a/config/bd/20240821-sel-const.toml b/config/bd/20240821-sel-const.toml
new file mode 100644
index 00000000..8594e93a
--- /dev/null
+++ b/config/bd/20240821-sel-const.toml
@@ -0,0 +1,12 @@
+birth_fn = "emevo.birth_and_death.SlopeELBirth"
+hazard_fn = "emevo.birth_and_death.ConstantBirth"
+
+[hazard_params]
+scale = 0.01
+alpha = 0.02
+slope = 0.2
+alpha_age = 2e-7
+beta = 4e-6
+
+[birth_params]
+const = 0.0002
\ No newline at end of file
diff --git a/config/bd/20240821-slope-04.toml b/config/bd/20240821-slope-04.toml
new file mode 100644
index 00000000..6dad2bec
--- /dev/null
+++ b/config/bd/20240821-slope-04.toml
@@ -0,0 +1,14 @@
+birth_fn = "emevo.birth_and_death.SlopeELBirth"
+hazard_fn = "emevo.birth_and_death.SlopeELGHazard"
+
+[hazard_params]
+scale = 0.01
+alpha = 0.02
+slope = 0.2
+alpha_age = 2e-7
+beta = 4e-6
+
+[birth_params]
+scale = 8e-4
+slope = 0.1
+const = -4e-4
\ No newline at end of file
diff --git a/src/emevo/birth_and_death.py b/src/emevo/birth_and_death.py
index 40b698f0..6294ba77 100644
--- a/src/emevo/birth_and_death.py
+++ b/src/emevo/birth_and_death.py
@@ -208,7 +208,7 @@ def cumulative(self, age: jax.Array, energy: jax.Array) -> jax.Array:
 class SlopeELBirth(BirthFunction):
     slope: float = 1.0
     scale: float = 0.1
-    const: float = 1.0
+    const: float = 0.0
 
     def __call__(self, age: jax.Array, energy: jax.Array) -> jax.Array:
         del age